Why do cats lick people?- VyWhy

Last updated on 2021-12-18 13:32:17


Sorry, it's not because they secretly love you.

Licking: cats are absolutely obsessed with it. In fact, research suggests an adult domestic feline can spend up to 8 per cent of their waking hours grooming their body with their tongue. Licking can also play an important social role with felines, with adults often licking each other just before copulating.

But what about humans: why do cats lick people? The good news: there’s no evidence to say your cat considers this any part of a pre-mating ritual. The bad news: scientists and cat behavioural experts aren’t completely sure why your cat might mop their little tongue against your face or hand.

However, while there’s no overarching and definitive explanation for this behaviour, there are several theories about why domestic felines lick humans. Spoiler: your cat doesn’t come off well in any of them.

There’s no one reason why your cat might lick you. However, there are three main theories why domestic felines engage in this behaviour:

  • They’re displaying they trust you.
  • They’re accessing biochemical information from you skin.
  • They’re marking you as another one of their possessions.

The trust theory

Yes, there’s a chance a cat may lick you to show they trust you. Or least to show they don’t consider you as serious competition.

“This type of licking is similar to a cat-to-cat behaviour known as allogrooming, which is basically mutual grooming. A cat will learn this from its mother when they’re a very young blind and deaf kitten. It’s basically to clean the kitten and strengthen social bonds,” says Dr David Sands, expert in animal psychology with over 25 years of clinical experience.

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“Because of these maternal origins, adult cats will only lick other cats they trust and are not in competition with. And this trusting grooming behaviour may be transferred onto a human.

“After all, cats are not sitting there saying ‘I’m a cat and you’re a human being’. To them, animals are either in competition with them or not. And licking shows you’re not in competition.” 

In other words, if your cat licks you, it’s not a positive sign of attachment. It’s just not a negative one (which is as good as it gets with a cat). 

cat licking © Getty
Helpful note: always think about the last place your cat might have licked before allowing this. © Getty

If in doubt, consider the University of Lincoln study tactfully titled Domestic Cats Do Not Show Signs of Secure Attachment to Their Owners.

When swapping 20 felines and their human owners, researchers found the cats appeared to bond as well with strangers (shown through behaviours such as play and mirroring) than with their actual owners.

The researchers concluded: “These results are consistent with the view that adult cats are typically quite autonomous, even in their social relationships, and not necessarily dependent on others to provide a sense of security and safety.”

The biochemical theory

While this sounds complicated, this is essentially the very simple idea that a cat will like you because they’re interested in whatever scent is on your hand.

Cat taste buds are so sensitive – they can pick up scents from our skins that could include pheromone secretions from other animals,” says Sands.

“It could also be that you’ve got salt, moisturiser or whatever you’ve just eaten on your hand. To cats, all these are interesting scents and licking allows them to check it out. That’s simply all it might be.” 

The possession play theory

Cats are, as Sands puts it, “scent machines from head to tail”. And their favourite smell? Their own. In fact, they love their own unique scent – which acts as an airborne fingerprint – so much they think it should supplant all others.

As Sands explains, this is why a cat may lick themselves after your stroke them – “it’s purely to get rid of your scent!” he says.

So much other cat behaviour comes down to possession and ownership. Everything that they do is very territorial,” Sands adds.

“Sometimes when cats groom other cats and people they’re scraping off scents and supplanting it with their own. It’s their way of marking and saying ‘This is mine! I own you!’”

He adds: “People always think cats rubbing themselves against you or things you touch are expressing love. But actually, cats are very possessing individuals. For them, the more they can brush past you and deposit their scent, the better!”

With a doctorate in ethology (animal psychology) at Liverpool University, Sands has over 25 years experience at his animal behavioural clinic. He is a Fellow of the Canine and Feline Behaviour Association (CFBA) and the Association for the Study of Animal Behaviour (ASAB).

Sands is also the author of Cats 500 Questions Answered, Hamlyn, £4).

Read more about the science of cats

Samsung Galaxy S22 Ultra review: With great power comes great …

16 hours ago · Samsung Galaxy S22 Ultra The display is AMOLED and supports 3,088 x 1,440 resolution. That means that if you’re willing to sacrifice battery life, you can experience a …

The Samsung Galaxy S22 Ultra is a device asking you to forget about money in exchange for the ultimate mobile experience. It’s flashy, extremely powerful and offering some of the highest specs available in pretty much every category… but with a price tag exceeding £1,100, is this luxury worth the price tag?

We spent a month with the phone to answer this exact question, testing how much use we got out of Samsung’s souped-up flagship and its high-end specs, asking whether this top-of-the-line Android experience is worth your time.

Wielding the S pen

The first thing any fan of Samsung will notice here is how much the Galaxy S22 Ultra looks like the now discontinued Note series. In many ways, this is the spiritual successor, blending the S and Note into one.

The Note series was a range of handsets that were powerful, tall, wide and came with a stylus included – consider it Samsung’s attempt at a phone for creatives or those needing a productivity powerhouse.

With the Samsung Galaxy S22 Ultra, there is the same shape and body as the Note 20 Ultra, and it is equally huge in size. This is great news for those who loved the Note design, and especially so for those who are after a large phone.

The Samsung Galaxy S22 Ultra with S pen stylus

However, the most obvious feature that makes this a Note of sorts is the S pen stylus – a beloved feature of the Note. Tucked up inside the phone, you simply push the end of it and the stylus will pop out.

The stylus is very much a love it or hate it feature and for me, I barely touched it. While it often felt more like an inconvenience for me, or I just completely forgot about it, there are some really smart things you can do with it… if you take the time to learn them.

Past the obvious scrolling and drawing, the S pen can be used to create gifs, snap, crop and save specific shots of your screen, extract large chunks of texts, edit photos, and even perform shortcuts by waving your pen in certain wizard-like movements.

Becoming a camera pro

Now that every powerful smartphone is like a mini-DSLR in your pocket, it can be hard to notice differences in camera quality between devices. The S22 Ultra, on the other hand, clearly stands out.

Turn the device over and you’ll see a lot of cameras, four to be exact. This includes a 108MP wide, two 10MP telephoto and a 12MP ultra-wide lens.

The device’s main trick is its zoom functions. You are able to zoom in by up to 100 times. While this is nothing new – Samsung has been able to do this on previous devices – the technology has been enhanced on this model. The image stabilisation means that even when you are extremely zoomed in, you’ll be able to keep steady, with the phone taking control and focusing on a target.

I tested this at a stadium concert where, despite being very far away, I could still sneak some close-up and pretty solid photos, pretending like I was much nearer than my cheap seats. When the lighting was better, I could get photos of buildings that were far away, focusing in on features, or details in clear quality.

Church spire zoomed in

The wide and ultra wide lenses offer equally as impressive photography. Through a feature called Adaptive Pixel, Samsung is able to take 9 pixels of information and combine them together. This allows for better colour and contrast on your photos. There is also an additional boost in terms of focus from the laser auto-focus sensor on the back of the phone. This together with the powerful processor in the phone means quick, high-quality photos in most situations, especially in the day. However, Samsung does have a tendency to go slightly heavy on saturation and colour, so expect your photos to occasionally look like they’ve been slapped by an Instagram filter.

Powerful internals and stylish designs

Considering the price tag, it will come as no surprise that each part of the Samsung Galaxy S22 Ultra is top-of-the-line.

The body of the device is a solid Armour Aluminium that feels tough and like it could take some force. With no case on, the phone has a smooth back that is surprisingly resistant to fingerprints.

The Ultra comes in at a whopping 6.8-inches and is noticeably thick. While this weight makes it feel sturdy and well-made, it is hard to hold and will be an absolute nightmare for those with smaller hands. I’m used to larger smartphones, but often found it poking out of the top of my pocket or having to shimmy the phone around to reach parts of the screen.

The display is AMOLED and supports 3,088 x 1,440 resolution. That means that if you’re willing to sacrifice battery life, you can experience a superior resolution and brightness saved for the best smartphones. However, you can lower that resolution at any time.

Zooming inside the handset, you’ll find a 5,000mAh battery which, while impressive in size and capacity, often drains at surprisingly fast rates, frequently only getting you through one day of usage. That’s not the end of the world but it is a shame for such an expensive device.

As for processing power, Samsung is using its own Exynos 2200 chipset. This is one of the most powerful options around for smartphones, meaning you’ll find few tasks that give you any problems. Demanding games, editing software and other big tasks all performed without any stutters. In fact, in the month that we had the phone, there was no point where the cracks started to show for performance, offering a fast and fluid experience at all times.

Is this the phone for you?

The Samsung Galaxy S22 Ultra is a double-edged sword. It doesn’t do anything in half measures. It goes all in on the camera, design, materials, processor, battery, and of course, price.

Do you need the Samsung Galaxy S22 Ultra? Realistically, no. This is an Android experience all about luxury, testing what happens when you throw cash at a smartphone to create the full package.

If you love phone technology and are after the best of the best, you’re in the right place. If for you, a price exceeding £1,000 seems insane, you’re not alone. Luckily, there are plenty of other fantastic top-tier Android devices to choose from (some of which we’ve listed below), all at slightly more affordable prices.

Alternatives to Samsung Galaxy S22 Ultra

iPhone 13 Pro Max

iPhone 13 Pro Max © Apple

If you’re willing to change sides, Apple actually has the best alternative to the Samsung Galaxy S22 Ultra – the iPhone 13 Pro Max. This handset has a more powerful processor, a better camera (although lacking the same zoom features), and has a battery that can last for a longer period of time.

Of course, you won’t get the same Android experience as you would with Samsung’s flagship, and Apple still has the black bar at the top of the screen, but it is otherwise Samsung’s biggest competitor for the best smartphone around.

Google Pixel 6 Pro

Google Pixel 6 Pro © Google

Google has slowly been improving its smartphones and with the Google Pixel 6 Pro, it feels like the closest it has got to matching Samsung. Much cheaper (and easier to hold), the Google Pixel 6 Pro doesn’t feel quite so overwhelming.

It has a powerful camera setup which, while lacking the zoom functionality of the Ultra, is one of the best point-and-shoots, offering consistently great photos.

While the battery life is slightly lacklustre, it is otherwise a fantastic choice for the price.

OnePlus 10 Pro

In terms of looks, overall feel and power, the OnePlus 10 Pro feels like the closest competitor you’ll get to the Samsung Galaxy S22 Ultra, and it comes at a much lower price.

It offers a great battery life and powerful processor, a high-end screen to rival the Ultra, and it even offers super-fast charging, getting your device from dead to fully charged in just an hour.

However, where it does fall short is in its camera performance. Despite having a collaboration with the legendary Hasselblad, the OnePlus 10 Pro fails to land the same kind of shots as its competitor.

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Can cats smile?

This behaviour is characterised by curled lips, a tilted head and squinting eyes – all of which can look like smiling. Cats may also bare their teeth in a kind of grin when feeling aggressive. Positive signs of a contented cat include purring, slow-blinking, paw-kneading, head-rubbing, meowing and tail-flicking – but never smiling! Read more:

Asked by: Lisa Milne (age 14), Oxford

Cats have the muscular ability to make facial expressions that resemble smiling, but it’s nothing to do with happiness! Certain odours, especially pheromone-rich ones like urine, can trigger the ‘flehmen response’, where cats draw scent particles to the roof of their mouth to be analysed by their extra sensory receptor, the Jacobson’s organ. This behaviour is characterised by curled lips, a tilted head and squinting eyes – all of which can look like smiling. Cats may also bare their teeth in a kind of grin when feeling aggressive. Positive signs of a contented cat include purring, slow-blinking, paw-kneading, head-rubbing, meowing and tail-flicking – but never smiling!

Read more:

  • Why do cats like small spaces?
  • Is it true that most ginger cats are male?

Why do cats like small spaces? © Getty Images

Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun facts.

What is Schrödinger's Cat?

The Schrödinger's cat thought experiment demonstrates the strange nature of quantum superposition. A cat is placed in a box with a vial of poison, which will be automatically smashed if a radioactive particle decays. Radioactive decay is one of the probability-driven aspects of quantum physics. We can't say when a given particle will decay, we only know the probability of …

The Schrödinger's cat thought experiment demonstrates the strange nature of quantum superposition. A cat is placed in a box with a vial of poison, which will be automatically smashed if a radioactive particle decays. Radioactive decay is one of the probability-driven aspects of quantum physics. We can't say when a given particle will decay, we only know the probability of it decaying in a certain period. After some time has elapsed, an unobserved particle will be in a superposition of decayed and not decayed states. All that exists before measurement (someone looking inside the box) is the probabilities. But since the life of the cat depends on the state of the particle, does this mean the kitty is simultaneously dead and alive?

In reality, we could never witness the cat being both alive and dead - as soon as we look in the box, the cat will be in just one state. And the practicalities of the experiment don't even allow for this. For the detector to be able to release the poison it would have to interact with the particle, forcing it to be either decayed or not decayed.

Despite its limitations, Schrödinger's cat gives us a feel for the weirdness of superposition, and while such a test wouldn't be possible with a complex organism like a cat, proposed experiments with a tardigrade could bring an aspect of the Schrödinger's cat experiment closer to reality.

Read more:

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How to stroke a cat - BBC Science Focus Magazine

Although people often think cats like being stroked at the base of their tail, research suggests that this can actually produce the most negative behavioural responses from cats,” says Finka. Alongside the lower back, Finka advises staying away from the belly, with your cat having evolved to keep this area protected.

What’s the best way to stroke a cat? Answer: probably not the way you’re doing it. Although you may think petting is a proven way to bond with your moggy, there's no guarantee they'll enjoy this physical contact.

As Dr Lauren Finka, cat behavioural expert from Nottingham Trent University, explains: “Although some cats certainly do like a lot of petting, lots of them probably don't want to be stroked the way that we would usually prefer to do it. They’re probably just very tolerant of it because of the benefits a relationship with you bring – think of all the food, treats and attention you give them.

"When it comes to petting, it’s best to remember that cats as a species aren’t inherently social or tactile."

In short: if you suspect your cat only puts up with your fondling to nab another bite of dinner, you’re probably completely right. Particularly if you’re consistently touching their back end.

“Granted, we know limited amounts about this from a scientific perspective. Although people often think cats like being stroked at the base of their tail, research suggests that this can actually produce the most negative behavioural responses from cats,” says Finka.

Alongside the lower back, Finka advises staying away from the belly, with your cat having evolved to keep this area protected. A cat’s vital organs are exposed at their navel, so they’re likely to see touching in this area as a threat.

Read more about the science of cats:

“With this said, there is a lot of variability in what cats enjoy. This is based on their personality, but also their early experiences. Cats that are well handled and socialised by humans from a young age ­– particularly during the ‘sensitive’ period of two to eight weeks of age – are usually more likely to enjoy handling,” says Finka.

“However, just because you have a friendly cat doesn’t mean they love being mollycoddled and squished. Even if a cat is meowing and rubbing against you, it doesn’t mean they’re fine with any sort of handling. You need to pay attention to their body language.”

How to stroke a cat © Getty

A cat showing positive body language (note the raised tail) © Getty

So, what subtle signs of annoyance – or, as feline behavioural experts call it, “negative arousal” – should you look out for? “When annoyed, cats might very sharply turn their head towards our hands. Or they may turn their heads to look at us. They might also simply freeze or stop actively encouraging the interaction (such as stop purring)” says Finka.

“Normally, when they're doing this, they're going to have ears that are not pointing directly forward – they might be slightly rotated or flattened.

“You may also notice nose licking, head shaking, alongside a sudden burst of grooming or rippled fur. A moving tail (either thrashing or twitching) held horizontally or close to the ground is also usually a negative sign (while a vertically raised tail is normally associated with 'positive arousal').”

“These relatively subtle indicators are happening quite often in many cats I observe being touched, but people usually tend to not focus on them – or misinterpret what they actually mean.”

What is the best way to stroke a cat?

As you might have guessed by now, there’s a lot you can do wrong when stroking a cat. However, there are areas where friendly cats may be most likely to enjoy being petted: around the face – predominantly, the cheeks, the base of the ears and under the chin.

“This is probably because these areas of the face contain a lot of skin glands that produce scent,” says Finka. “Cats are very motivated to use these areas to spread their scent, so these regions probably intrinsically feel quite nice to be stimulated.”

Of course, your cat, being the absolute weirdo it is, may also enjoy being stroked in other areas. If in doubt, looking for “positive arousal” signals: purring, rubbing against you, kneading and gentle tail waving side-to-side are all good signs.

Overall, when it comes to stroking your cat, it may be best to consider Finka’s petting guidelines (currently being researched for the benefit of felines at Battersea Dogs and Cats Home).

And you’re not going to believe the acronym it follows…

C: Provide the cat with choice and control during the interaction.

  • Gently offer your hand to the cat, allow the cat to approach you, and let them choose if they want to interact or not.
  • If the cat wants to be touched, they will rub against you. If they don’t make contact, avoid stroking the cat.
  • Allow the cat to control how much you stroke them. If stroking the cat, briefly pause every 3-5 seconds to ‘check in’ with the cat – when you stop stroking them, do they rub against you to ask for more? If not, they may be ready for a break.

A: Pay attention to the cat’s behaviour and body language; the following are also signs that the cat may need a little break:

  • They go a bit still and stop purring, leaning in for strokes or rubbing against you
  • The cat moves away from you
  • Their ears become flattened or rotate backwards
  • They shake their head
  • The fur on their back appears to ripple
  • They lick their nose
  • They go a bit still, and stop purring or rubbing against you
  • They sharply turn their head to face you or your hand
  • They suddenly start grooming themselves, lasting only a few seconds

T: Think about where you’re touching the cat.

  • Most friendly cats will prefer being touched under their chin, around their cheeks and at the base of their ears, so try to stick mainly to these areas.
  • Avoid the base of the tail and tummy, and be cautious then touching the cat’s back, legs and tail – pay close attention to their body language to see if they appear comfortable.

Follow this guidance and, who knows, your cat may come to truly love you. Well, enough to cross your off their lengthy ‘humans that must be destroyed’ list anyway.

About Dr Lauren Finka

Dr Lauren Finka is a cat behavioural expert from Nottingham Trent University. She has over a decade’s experience working academically with felines.

Finka is also a specialist consultant for Battersea Dogs and Cats Home and also works with International Cat Care (ICatCare) and International Society for Feline Medicine (ISFM) on various behaviour and welfare projects.

Read more about the science of cats

What's the longest a cat can live for?

The lifespan of a domestic cat – the maximum length an individual can expect to live – is around 30 years. However, this doesn’t mean that the average cat will live this long: the real length of a feline’s life is influenced by genetics, environment and lifestyle, as well as injury and illness. Cats tend to live around 15 years, on average.

The lifespan of a domestic cat – the maximum length an individual can expect to live – is around 30 years. However, this doesn't mean that the average cat will live this long: the real length of a feline's life is influenced by genetics, environment and lifestyle, as well as injury and illness.

Cats tend to live around 15 years, on average.

As in humans, female cats tend to live for longer than male cats. Neutered cats are also likely to live for longer than intact ones, and pure breed cats are less likely to live as long as crossbreeds.

Top 5 oldest cats

Creme Puff (38 years and 3 days)

3 August 1967 – 6 August 2005

Guinness World Records lists Creme Puff, a tabby mix, as the oldest cat ever to live. She was owned by Jake Perry of Austin, Texas.

Baby (38 years)

1970 – March 2008

In second place is Baby, a black domestic shorthair who lived in the USA and also reached 38 years old.

Puss (36 years and 1 day)

28 November 1903 – 29 November 1939

The 1990 edition of the Guinness Book of World Records listed Puss as the oldest cat ever recorded. The tabby was owned by Mrs T Holway of Devon, and died the day after his 36th birthday.

May-June 1923 – 5 November 1957

In the same edition, Guinness features Ma, a female tabby owned by Mrs Alice St George Moore, also of Devon.

Granpa Rexs Allen (34 years, 2 months)

Also owned by Jake Perry, Granpa Rexa Allen was a Sphynx-Devon Rex who lived to the age of 34. Perry claims that the cat's diet was the secret to its long life: eggs, broccoli, bacon and coffee with cream.

In pictures: The most iconic volcanic eruptions of 2021 ...

Subscribe to BBC Science Focus Magazine and get 6 issues for just £9.99. Volcanologist Prof Bill McGuire takes a closer look at some of the iconic eruptions that took place in 2021. With Italy’s iconic Etna volcano erupting at the beginning of the year, followed by the lava flows of La Palma making headlines for weeks in autumn, then ...

With Italy’s iconic Etna volcano erupting at the beginning of the year, followed by the lava flows of La Palma making headlines for weeks in autumn, then activity starting at Hunga Tonga-Hunga Ha’apai in late December, it felt like 2021 was a particularly big year for the planet’s volcanoes.

When we look at the statistics, however, we see that this level of volcanic activity is nothing special. In 2021, 80 eruptions occurred at 75 volcanoes, with 32 new eruptions recorded. This is pretty much par for the course, and looking at the year-on-year figures for the past few decades, there is no indication that volcanic activity is increasing.

Still, the volcanoes of 2021 seemed to capture the attention of the world’s media, and blew our minds at a time when much of the world was still reeling in the aftermath of the COVID pandemic, reminding us once again of the awesome power of nature.

Read more about volcanoes:

Mount Etna, Italy

Mount Etna volcano erupting

© Getty Images

Something is always happening at Sicily’s Mount Etna, and 2021 was no different. Etna demonstrates two different types of activity: ash explosions and overspilling lava flows from one or more of the four summit craters, and larger volume lava flows lower down on the flanks.

During 2021, the action was all at the summit, where spectacular lava fountains up to a kilometre high often lit up the sky over eastern Sicily. Periodically, more violent blasts launched huge columns of gas and debris high into the stratosphere, deluging surrounding communities in ash, and closing Catania airport at the foot of the volcano on a number of occasions.

Etna’s eruptions have certainly become more violent in recent years, and there may be further activity in 2022.

Fagradalsfjall, Iceland

Fagradalsfall volcano, Iceland

© Getty Images

An eruption in Iceland is hardly news, but this one was different. For the first time in more than 800 years, lava was flowing once again on the Reykjanes Peninsula. Following a period of unrest, lava reached the surface in mid-March 2021, via a system of new fissures.

Activity soon became focused at one point, rapidly building a cone that reached a height of more than 330 metres in just nine months. The eruption site became a magnet for tourists, but Reykjavik residents did not need to travel, as jets of magma more than 300 metres high could be seen from the capital 60 kilometres away.

The eruption eventually ended in September after 181 days, but the return of activity to this part of the island suggests that more eruptions could be on the way in due course.

Semeru, Indonesia

Semeru volcano, Indonesia

© Getty Images

Located in southern Java, Semeru is an archetypal, steep-sided, volcanic cone, beloved of tourists and hikers alike. It is also very dangerous. Semeru’s eruptions tend to be moderately explosive rather than huge, but often lead to loss of life.

The volcano has been almost continuously active since 1967, the latest outburst beginning in early December 2021, when heavy rains contributed to the collapse of the summit lava dome. This triggered an explosive eruption that sent a column of ash and debris to a height of more than 12 kilometres, and fed pyroclastic flows and mudflows.

Travelling at speed down the flanks, these soon reached the villages at the foot of the volcano. Similar activity continued over the following month or so, leading to the destruction of 5,200 buildings, causing more than 70 deaths, and displacing in excess of 10,000 people. Semeru continues to be active as of February 2022.

Kilauea, Hawaii

Kilauea volcano, Hawaii

© Getty Images

If you are determined to see flowing lava, Kilauea in Hawaii is your best bet. Between 1983 and 2018 the volcano was in almost continuous eruption, spewing out lava that covered more than 100 square kilometres, buried nearly 800 homes, and remodelled the coastline.

After a short pause, a new eruption began in December 2020 at the summit’s Halema’uma’u crater. Active vents in the crater floor began to fill it with lava, so that by the end of February 2021, the crater was occupied by a huge lake of churning lava more than 200 metres deep.

Things quietened down after May, but a new eruption began in September 2021, when new fissures opened within the crater, feeding fountains of lava that reached heights of more than 60 metres. As the level of lava in the crater rose, all but one of the vents became submerged, leaving a single vent to continue to ooze lava.

Soufrière, St Vincent

Soufrière volcano, St Vincent

© Alamy

Eruptions of St Vincent’s Soufrière volcano can be deadly. In 1902, a major blast killed close to 1,700 people, but when a smaller eruption began in 1979, the authorities were better prepared, and timely evacuation meant that there were no deaths.

Following more than four decades of quiet, a new eruption began just after Christmas 2020. In early April 2021, a violent explosion obliterated a colossal lava dome that had grown over the previous three months, launching an eight-kilometre-high eruption column that dumped ash across the island and closed the airport on neighbouring Barbados.

Big explosions continued over the next few weeks, feeding pyroclastic flows and mudflows, before activity died down at the end of the month. The eruption was as big as that of 1902, and could have been similarly lethal, if not for the fact that more than 16,000 people were evacuated from the highest risk areas.

Hunga Tonga-Hunga Ha’apai, Tonga

Hunga Tonga-Hunga Ha'apai volcano, Tonga

© Shutterstock

Prior to December 2021, the only visible bits of this submarine volcano were the tiny islands of Hunga Tonga and Hunga Ha’apai. Soon, even these were gone. Towards the end of the month, violent explosions tore the islands apart and dumped ash across the Tonga archipelago.

The eruption climaxed on 15 January 2022, when a colossal detonation, likely caused by the mixing of magma and seawater, spawned shock waves that circled the planet four times, and was heard as far afield as Alaska, 6,000 kilometres away. A series of tsunamis followed, which reached heights of 15 metres on some islands, and crossed the Pacific to take two lives in Peru.

Because of eruption damage to an undersea cable, communication with Tonga remains poor, and it may be some time before the true extent of the damage is known.

Nyiragongo, DRC

Nyiragongo volcano, DRC

© Reuters

Nyiragongo is an impressive volcano, having a kilometre-wide summit crater filled by a lava lake that periodically drains, feeding lava flows that often threaten the neighbouring city of Goma. In 2002, such an eruption destroyed several thousand homes and led to the evacuation of a quarter of a million residents.

The 2021 eruption began in May and followed a similar path. Drainage of the lava lake coincided with the opening of fissures low down on the volcano’s south flank, from which rapidly flowing lava issued. Within hours, the flows had reached the northern outskirts of Goma, leading – ultimately – to the destruction of more than 3,500 homes and the displacement of 20,000 people.

Lava production stopped after a couple of days, but strong earthquakes followed, accompanied by the opening up of ground cracks in the city itself. With a new lava lake growing, the stage is already being set for the next eruption.

Taal, Philippines

Taal volcano, Philippines

© Shutterstock

The active cone of Taal volcano is pretty much unique in that it forms a low-lying island – known as Volcano Island – at the centre of a huge lake-filled crater formed by a mega-blast during prehistoric times.

As such, it presents a unique set of hazards, most notably surges of boiling water, gas and ash that scoot across the lake surface before crashing into the shore. More than 1,000 lives were lost to such surges in 1911, and a further 100 or so in the 1965 eruption, which obliterated villages around the lake edge.

The latest eruption began in January 2020, when a violent blast dumped ash across Manila, the capital of the Philippines, and then erupted again in July 2021. Since then, it has continued to periodically blast out clouds of ash and steam, and to generate a sulphurous volcanic fog (known as vog), causing health problems for the local inhabitants.

Fukutoku-Oka-no-Ba, Japan

Fukutoku-Oka-no-Ba volcano, Japan

© Getty Images

Hidden away in the Bonin Islands, 1,500 kilometres south of Tokyo, the existence of this submarine volcano has barely impinged upon most people’s radars – even those of most volcanologists. Fukutoku is something of a now-you-see-it, now-you-don’t volcano, at times taking the form of a small island, at others marked only by a patch of discoloured water.

Half a dozen small eruptions were recorded in the first decade of the century, but the volcano had been quiet before waking with a bang in August 2021. The colossal 16-kilometre-high column of ash blasted into the atmosphere was impossible to ignore, as were the immense rafts of pumice that covered the surface of the sea near the eruption site. Seemingly nothing more than a curiosity at first, the pumice rafts reached the Japanese mainland a couple of months later, clogging harbours, contaminating fisheries and damaging hundreds of vessels.

La Palma, Canary Islands

La Palma volcano, Canary Islands

© Shutterstock

Eruptions at La Palma’s Cumbre Vieja volcano – the most active in the archipelago – tend to occur in clusters separated by a few hundred years, the last one ending in the early 18th Century. Following a couple of hundred years of quiet, the volcano erupted again in 1949 and 1971. Since 2017 it had been restless again, so when magma broke the surface in September 2021, it was not unexpected.

Eruptive activity was a mix of ash explosions, lava fountaining, and the voluminous production of flowing lava. Over the course of three months or so, successive flows destroyed more than 5,000 buildings, including all those making up the town of Todoque, and built a new delta on the island’s western coast. The total cost of the 85-day eruption is estimated at close to €1bn, and its official ending on 25 December came as a much-needed Christmas present for the island’s long-suffering inhabitants.

Read more about natural disasters:

The science-backed ways to keep slugs off your plants ...

This chemical causes the slugs and snails to stop eating. How can I stop slugs eating my plants? According to Dr Hayley Jones, an entomologist at the Royal Horticultural Society (RHS) who researches slugs and snails, slug pellets should always be the last option for controlling slugs, and it’s better to start with preventative measures.

As of 1 April, slug pellets containing metaldehyde can no longer be owned or sold in the UK. The ban follows the advice from the UK Expert Committee on Pesticides (ECP) and the Health and Safety Executive (HSE), and has come into force because the chemical has an unacceptable impact on the environment and wildlife.

Metaldehyde is harmful to birds, amphibians and mammals – including hedgehogs, cats and dogs – that directly consume the pellets, or eat slugs or other creatures that have been contaminated by them.

Metaldehyde works by disrupting the mucus production in slugs and snails. This reduces their ability to digest food and move around, and also makes them susceptible to dehydration. Slugs and snails that have eaten the chemical will tend to die within days.

Slug pellets based on less toxic ferric phosphate are still allowed. This chemical causes the slugs and snails to stop eating.

How can I stop slugs eating my plants?

According to Dr Hayley Jones, an entomologist at the Royal Horticultural Society (RHS) who researches slugs and snails, slug pellets should always be the last option for controlling slugs, and it’s better to start with preventative measures.

“If you’re planting out new plants, grow your seedlings on until they're bigger and sturdier so that they're not going to just die straight away if they get nibbled a bit,” she says. “Once you've got your plants in and they're being nibbled, go out at night to catch them [the slugs] in the act and pick them off, relocate them or dispose of them as you see fit.”

It's also worth researching plants that are less attractive to slugs. Generally, shrubby or woody plants, or those with waxy or furry leaves, are less tasty. Here are some common slug-resistant plants, recommended by the RHS:

  • Snapdragons
  • Foxgloves
  • Fennel
  • Bleeding heart
  • Scabious
  • Nasturtiums
  • Pelargoniums
  • Geraniums
  • Fuchsias
  • Aquilegia

If that doesn’t work, it is possible to buy a nematode biological control agent that you mix into water and sprinkle over your plants. The nematodes in the mixture are parasites of slugs. It doesn't really affect snails because they don't hide underground in the way that slugs do,” says Jones. “But it will be good for treating a raised veggie bed or something like that. As well as killing the slugs on the plants, it will kill the slugs in the bed.”

The nematode is naturally occurring in the UK, so when you apply it to the soil, you’re bumping up the levels that were there before.

“It's actually quite interesting because it's not the parasite itself that kills the slug,” says Jones. “The parasite carries bacteria, and when the nematode gets into the slug’s body, it releases the bacteria. The bacteria kill the slug and then essentially the nematode breeds in the soupy slug mess that's left behind.”

Gloved hand holding slug

Collecting slugs by hand and disposing of them is an effective way to keep their numbers down © Getty Images

The truth about salt, eggshells and copper tape…

But what about ‘traditional’ control agents – like eggshells, salt and copper tape – to keep slugs and snails off your lettuces?

“So far, there is not much scientific evidence in their favour. So for copper, there have been some studies that show copper working and some that show it not working, including a study that I did,” says Jones. “I tested copper, bark mulch, gravel, eggshells and wool pellets on lettuce. And at the end of six weeks of lettuce growth, there was no significant difference between the ones with the barriers and the ones that had nothing at all.

“The idea is supposed to be that slugs and snails don’t like sharp, rough or very dry surfaces, but as long as they're well hydrated, they can just produce extra mucus to help them overcome it. So even if it is kind of uncomfortable, if what's on the other side is tasty enough, they will they will crawl over it.

“Salt is an interesting one. I'm never quite sure what to do with that because I don't know how people use salt. The main problem with salt is that it is bad for your soil and potentially bad for your plants.”

As for beer traps, there are many studies that show you can catch lots of slugs in that way, but Jones has not yet found any research that shows plants are less damaged as a result of the trap being there.

“This is a knowledge gap I’m hoping to fill,” she says. “It maybe does have promise, but there's a chance that it might not be helpful because it's attracting the wrong kind of slugs, or because it's actually attracting them from farther away. Plus, there’s also the risk you’ll catch ground beetles and other non-target animals.”

Why are slugs important?

In the UK, there are around 44 species of land-based slugs, and of those, only nine cause any significant damage to plants. Most of them will eat rotting material, as well as fungi and algae, making them part of the clean-up crew in our gardens.

The one that causes the most problems for gardeners is the grey field slug, which is around four centimetres long when fully grown. They can often be found hiding out in lettuces and cabbages, as they are small enough to lurk within the leaves.

But is it time for us to stop fighting the slugs? After all, they’re an important component of food webs, with thrushes and other birds, hedgehogs, badgers, slow worms, frogs, toads, and all other kinds of things feeding on them.

“They are part of the ecosystem. The climate in the UK is ideal for slugs, kind of damp and middling temperature. They've been around longer than gardens have,” says Jones. “You'll never be able to get rid of slugs and snails from your garden, and you don't know what the unintended consequences would be if you could. At least take a bit more of a neutral stance: when you see a slug, recognise that it is not necessarily doing harm!"

Read more about slugs and snails:

  • Why do slugs and snails produce a silver trail?
  • Do snails have teeth?

About our expert

Dr Hayley Jones is an entomologist at the Royal Horticultural Society. She leads their research into gastropods (slugs and snails) in the garden.
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