Credit: Houston Zoo Blogs.

The Secret Superpower of the World’s Cutest Animal

Venom is generally thought to be the property of snakes, lizards, and various creepy-crawlies. But they don’t have exclusive rights, and mammals are not to be outdone. Some members of our hairy brethren have also shown a propensity for envenomating the unlucky. These would-be poisoners include the American shrew, the Haitian solenodon, and the most famous venomous mammal, the platypus.

The Haitian solenodon is a curious looking critter.

The Haitian solenodon is a curious looking critter. Credit: Eladio Fernandez

The playtpus, and other venomous mammals, are a little weird looking – weird enough that their poisonous bites (or elbow spurs, for the platypus) don’t seem too out of character. But the other venomous mammal? The new kid on the block? It’s not odd-looking – in fact, it’s probably the cutest animal on the entire planet: the slow loris.

Credit: Houston Zoo Blogs.

Credit: Houston Zoo Blogs.

Slow lorises are a collection of primate species that live in South East Asia. Currently, there are eight recognized species (up from one not too long ago), and the number will likely increase again as more research is done on them. They are a comparatively old genus of primate, related to lemurs and galagos (the adorable weirdos of the Primate order). They’re nocturnal, mostly solitary, and move (slowly) through the trees of tropical rainforests, and increasingly, fields of crops, feeding on insects and generally minding their own business.

They’re not monkeys, and will be sad if you call them monkeys, so please don’t.

Do you know what else makes slow lorises sad? Captivity.

Do you know what else makes slow lorises sad? Captivity.

Slow lorises have been in the news recently, thanks to singer Rihanna’s ill-informed decision to pose for a photo with one in Thailand, and then post it on Instagram (which led to the arrest of the people smuggling them, so that’s a happy ending for everyone who isn’t going to a Thai jail now). Prior to that, slow lorises were probably best known for that YouTube video of a loris being ‘tickled’. I’m not going to link to it, because that guy doesn’t really need anymore attention, but if you watch it, you should know that the loris isn’t raising its arms because it wants to be tickled – it’s raising its arms as a defense mechanism.

Now, as far as a defense mechanism goes, surrendering is not necessarily a winning strategy in the “red in tooth-and-claw” natural kingdom. But the slow loris has a trump card – its not raising its arms to surrender, but to access its venom glands.

In the wild, this sort of behaviour generally just gets you eaten.

In the wild, this sort of behaviour generally just gets you eaten…

On the arms of a slow loris, about where you’d get a bicep tattoo (if you were that sort of person), there are venom glands. These glands secrete Part A of the slow lorises venom. But there are problems with your body constantly leaking venom – for example, it makes cuddling difficult. So for the venom to become active, slow lorises mix it with their saliva (Part B). By licking the glands on their arms, slow lorises activate the venom, giving themselves a toxic bite.

...unless you have venomous armpits. Credit: Helga Schulze, in Krane et al 2003.

…unless you have venomous armpits. Credit: Helga Schulze, in Krane et al 2003.

And it can be a nasty bite, for such an adorable little animal. There has been at least one reported human death from a slow loris bite, and even if you don’t die, it is going to swell, pus, bleed, fester, and hurt for a long time. Which serves you right for trying to harass them. When smugglers catch slow lorises for the pet trade, they surgically remove the teeth to prevent bites to the  privileged idiots who illegally buy the animals later on.

The venom serves a number of purposes. It is strong enough to kill small prey, although loris teeth likely do that just as well. During the mating season, male lorises fight violently for access to females, and use their venomous bite to cause serious damage to one another. But again, their teeth would get the job done just as well. Producing venom is energetically-expensive, and would be difficult to favour evolutionarily without it providing a major survival or reproductive advantage at some point in a lorises lifetime. And if there’s one advantage a slow loris is always looking for, its how to not be eaten.

No, it's not trying to seduce you. It's loading up on venom (which you can see glistening around the nose). Credit: Anna Nekaris

No, it’s not trying to seduce you. It’s loading up on venom (which you can see glistening around the nose). Credit: Anna Nekaris

Lorises are small, slow, and vulnerable to many predators. They prefer to avoid confrontation, but that’s not always possible. So when travelling through the forest, the lorises will coat their fur in a layer of venom by licking themselves all over. Predators can smell the venom-wash, and are encouraged to find something else to eat. It’s so effective that slow lorises can saunter casually past the baleful glare of a jungle cat or a sunbear without fear – something that all tiny herbivores wish they could pull off with such aplomb. Rather than being an offensive weapon, the venom of a slow loris is defensive in function.

On the other hand, they shouldn’t get too cocky. While cats and bears shy away from the scent of slow loris venom, orangutans – another predator of lorises – seem to treat it like a healthy dollop of hot sauce on-top of a cute little appetizer. Sometimes even the cutest animal in the world can’t catch a break.

Oops. Credit: Madeleine Hardus.

Oops. Credit: Madeleine Hardus.

Featured photo by Houston Zoo Blogs


Dufton, Mark J. “Venomous Mammals.” Pharmacology & Therapeutics 53, no. 2 (1992): 199–215.

Klotz, John H., Stephen A. Klotz, and Jacob L. Pinnas. “Animal Bites and Stings with Anaphylactic Potential.” The Journal of Emergency Medicine 36, no. 2 (February 2009): 148–156. doi:10.1016/j.jemermed.2007.06.018.

Nekaris, Anne-Isola, Richard S Moore, Johanna Rode, and Bryan G Fry. “Mad, Bad and Dangerous to Know: The Biochemistry, Ecology and Evolution of Slow Loris Venom.” Journal of Venomous Animals and Toxins Including Tropical Diseases 19, no. 1 (2013): 21. doi:10.1186/1678-9199-19-21.

Whittington, C. M., A. T. Papenfuss, P. Bansal, A. M. Torres, E. S.W. Wong, J. E. Deakin, T. Graves, et al. “Defensins and the Convergent Evolution of Platypus and Reptile Venom Genes.” Genome Research 18, no. 6 (May 7, 2008): 986–994. doi:10.1101/gr.7149808.

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