Forget lions, tigers, bears, crocodiles and other apex predators. Sometimes it’s the quiet ones you have to watch says Stuart Blackman. Here’s our pick of the animals that you’d least expect to be a risk to humans…
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10 unlikely killers
Tortoise
Tortoises’ slow-and-steady approach to life might fare them well in fictional races with hares, but it doesn’t equip them well for a life of violence. Even so, death by tortoise has a long history. The ancient Greek dramatist Aeschylus is said to have been killed by one that was dropped on his head by an eagle in 456 BC.
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More recently, in the USA, there have been at least four recorded incidents since 2016 involving tortoises or turtles crashing through car windscreens after being flipped up into the air by other vehicles. None of these resulted in human fatalities and remarkably only a single turtle lost its life.
However, in December 2024, a three-year-old child playing in a garden was killed by a pet turtle falling from a high-rise building in Shaoguan, China.
Deer
What animal kills the most people in the US? Alligators? Wolves? Sharks? Snakes? Mountain lions? Well, it’s none of those. In fact, all wild predators combined account for an average of only eight human deaths per year. Which is nothing compared with the 440 people who die annually in vehicle collisions with deer.
Ironically, predators are helping to solve the problem. Traffic accidents involving deer are declining in regions where wolf populations are expanding. In Wisconsin, for example, wolf re-colonisation has cut deer–vehicle collisions by almost a quarter.
This is partly because wolves help keep deer numbers down by hunting them. But more importantly, they tend to use roads, tracks, pipelines and other linear features of the landscape as travel corridors, which is enough in itself to keep the deer away from traffic.
Meanwhile, just a single person – a jogger in Alaska in 2010 - has been killed by wolves in the past 100 years.
Marmot
In the age of antibiotics, plague isn’t the threat to life and civilisations that it has been over recent millennia, but it hasn’t been entirely consigned to history. A few hundred infections are reported around the world each year, and many of those have a surprising source.
Marmots are large, plump ground-squirrels that dig their burrows in alpine meadows across much of North America, Europe and Asia and are famous for their whistling calls.
The bacterium that causes plague, Yersinia pestis, circulates in marmot colonies, passing via fleas, and can spill over into humans when animals are hunted or handled.
43 of the 73 human cases of plague reported in Mongolia between 1998 and 2015 were associated with close contact with infected marmots. In 2020, a teenage boy died of the disease after eating uncooked marmot meat .
Sow loris
Dangerous animals don’t come any cuter than the slow lorises of Southeast Asia.
These woolly, saucer-eyed relatives of the lemurs are the only known venomous primates, wielding a bite that can cause excruciating pain, anaphylactic shock, internal bleeding and, in at least one case, reported by a medical doctor working in Thailand, death.
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The venom is produced by modified sweat glands near the loris’s elbow. The animal licks the glands to mix the venom with its saliva, which is then delivered by needle-sharp teeth.
Why an animal that feeds on tree sap, fruit and insects needs venom is not entirely clear. It may be deployed in territorial disputes with rivals or provide defence against predators.
Beaver
Plump, buck-toothed and friendly-faced, beavers are strict vegetarians with a reputation for industriousness and famed for their knack for reshaping landscapes with their dam-building endeavours.
But when cornered or surprised, these large rodents can defend themselves with startling ferocity using chisel-like teeth designed for felling trees.
In 2013, a fisherman in Belarus died after a beaver bit through a major artery in his thigh. The attack was not entirely unprovoked. The man was bitten several times when he tried to grab the animal for a photograph, and he bled to death before help arrived - perhaps it belongs on our idiotic and reckless wildlife acts list
Other attacks, often involving rabid animals, have been recorded in North America, but there are no records of any fatalities.
Cows
Docile is a word that is often used to describe cows. And yet they kill more people in the UK than any other animal.
Over the last decade or two, cows have killed an average of about six people each year (75 per cent of them farmers), by trampling or crushing against walls, fencing or machinery.
Dogs, in second place, have killed fewer than four (although there has been an uptick during the 2020s). The difference becomes more pronounced when you take into account that dogs (13 million) significantly outnumber cattle (9 million) in the UK, in which case, on a per-head basis, cattle kill about twice as many people.
Cows are big, strong and heavy, so when accidents happen, they have the potential to be disastrous. But also, as prey animals, they are wired to defend themselves from perceived threats. Mothers particularly can be fiercely protective of their calves.
But don’t let any of that put you off a walk in the country, which remains far safer than a drive to the supermarket.
Slugs
Slugs are hardly intimidating creatures, even if they do tend to induce a bit of an ick response. And perhaps there’s a good reason that many of us find slugs a bit disgusting. Because these slimy, shell-less molluscs do occasionally kill people – especially people who try to eat them.
Slugs are the hosts of a stage in the lifecycle of a parasite called the rat lungworm. This tiny nematode normally cycles between rodents and molluscs, but should it get into a human, it takes a wrong turn, migrating to the brain where it causes a type of meningitis.
One widely-reported case involved an Australian rugby player who was paralysed by the infection after swallowing a slug in a moment of drunken bravado and died eight years later.
More than 2000 cases have been documented worldwide, most of them in Thailand, where there is a culture of eating raw or undercooked snails with alcohol
Platypus
With its duck-like bill and talent for laying eggs, the platypus is a funny animal in both the ‘ha-ha’ and ‘peculiar’ senses of the word. But it is also quite capable of inflicting serious damage on anyone who gets too close, by means of a horny spur on each hind leg that it plunges into the flesh of assailants to inject a potent venom.
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This venom is reported to be powerful enough to kill a dog, if not a human. The pain, though, which can endure for weeks and is resistant to morphine, is by all accounts excruciating. According to Keith Payne, an Australian war hero who got spurred while trying to rescue a platypus while on a fishing trip, it’s worse than getting hit by shrapnel.
Only the males possess the spurs, and the venom glands are most productive during the breeding season, suggesting that the weaponry is used primarily in violent disputes with rivals.
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