The World’s 10 Most Venomous Mammals

Most Venomous Mammals – Platypus

Written by Peter Pchemut

Updated: November 28, 2023

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When most people think of venomous animals, the first things that come to mind are snakes, spiders, and insects. Admittedly, those are the most prevalent venom-carrying animals, but they are not by any means the only ones. Did you know that there are a number of venomous mammals as well?

Venom and poison are frequently used interchangeably, but that is not technically correct. Poison can be absorbed through the skin, inhaled, or taken in through a variety of means, but venom is injected into the body of the attacker or prey via a bite or another method. Keep reading to learn about the top 10 most venomous mammals!

Infographic of the Most Venomous Mammals in the World
The platypus is the most venomous mammal on the planet.

10. Maned Rat

maned rat

The maned rat rubs its back in poisonous tree sap, and predators get a mouthful when they attack.

©Kevin Deacon / CC BY-SA 3.0 – Original / License

The maned rat holds the tenth place on this list solely because it is not technically venomous. However, these poisonous mammals defend themselves by injecting those that would prey on them with a poison that is obtained through an interesting method. Native to East Africa, this rat can grow up to almost two feet long with a tail that’s an additional foot in length.

The maned rat searches for poison arrow trees chews on them to release sap from the tree and then rubs its back in the poisonous sap. When threatened, the rat arches its back much like a cat and exposes the poison coated hair. The unwary attacker receives a mouthful of poison which can kill or incapacitate it depending on the size of the animal and the quantity of poison it receives. These poisonous mammals have a conservation status of Least Concern according to the IUCN.

9. Vampire Bats

A vampire bat with its mouth open on the side of a rock.

A vampire bat’s venom coagulates the blood of its prey so the vampire bat can feed more freely.

©Michael Lynch/

Bats are the only flying mammal, and vampire bats are therefore the only venomous flying mammal. There are several species of venomous vampire bat such as the hairy-legged vampire bat, the white-winged vampire bat, and the common vampire. All venomous species prey on cows, pigs, and other forms of livestock.

Other animals’ blood is the “lifeblood” of vampire bats. In fact, if they go more than two days without it, they die. And their appetites are voracious. In one evening, they will drink up to half their body weight in blood.

Their venom is not directly harmful in that it doesn’t cause pain or paralysis like some of the other mammals on this list, but it aids the bat by preventing the blood of its prey from coagulating after the bite. This allows the vampire bat to satiate itself on free-flowing blood in the bite wound. While their bites aren’t harmful in general, they can cause infection or disease in the victim. Check out more interesting facts about the Central and South American vampire bat species here.

8. Eurasian Water Shrew

A Eurasian water shrew standing on the top of a rock in a body of water.

The Eurasian water shrew’s saliva can paralyze prey but is not generally as threat to humans.


The Eurasian water shrew lives all across northern Eurasia. It burrows into stream banks and makes its home in similar aquatic environments. This venomous mammal has bite saliva that paralyzes its prey. While it can bite or scratch humans with its claws, its small size means that is it not a threat to humans. Weighing in at less than half an ounce and measuring just 2 to 4 inches in length, this tiny mammal should still be handled with protective gloves.

7. Mediterranean Water Shrew

A Mediterranean water shrew standing on the top of a rock in a body of water.

Mediterranean water shrews use venom to paralyze their prey, which consists of fish and other marine life.


Mediterranean water shrews thrive in the waters of the Mediterranean Sea and live in countries that border it such as Spain and Italy. It feeds on fish and other marine life using venom that has paralytic effects. It can administer enough venom in one bite to kill certain fish outright. Slightly smaller than its Eurasian counterpart, the Mediterranean shrew grows to about 3 inches and weighs under half an ounce.

The water shrew is quite unusual among mammals because it has a venomous bite. The poison in its saliva is strong enough to immobilise frogs and small fish. It can tackle prey up to 60 times heavier than itself, including newts, frogs, crustaceans and snails.

6. Short-Tailed Shrews

A Northern short-tailed shrew standing on the ground near green vegetation.

Several species of short-tailed shrew inhabit North America, and they all have venomous saliva that paralyzes prey.

©Joe McDonald/

There are several species of short-tailed shrew that inhabit various parts of the United States and North America. All of these venomous shrew species hunt with venom-saturated saliva that has paralytic effects on their prey.

The northern short-tailed shrew lives in the northeast of North America, and Elliot’s short-tailed shrew is a resident of the central United States. Both animals measure up to 5 inches long and weigh under 1 ounce.

The southern short-tailed shrew lives in the southeastern United States and the Everglades short-tailed shrew makes it home predominantly in Florida. These venomous mammals grow to be 3 to 5 inches in length, but they weigh approximately 3 ounces. That’s much heavier than their cousins.

These animals all have a conservation status of Least Concern.

5. European Mole

A European mole with dirt on its head, exiting a burrow.

European moles inject their prey with a paralytic saliva and drag them into their burrows to feast over time.

©Bildagentur Zoonar GmbH/

The European mole earns a higher spot here than the various shrews simply because of its size. An inhabitant of the United Kingdom and Russia, this venomous mammal grows to between 4 and 6 inches with a tail that adds another inch, and they weigh about 3 to 5 ounces. European moles avoid humans at all costs, but they will inject their victims with a paralytic saliva by biting them when hunting or threatened. These moles drag their prey of mice and rabbits back to their burrows where they will feast on them over time.

Read more about moles here.

4. Cuban Solenodon

A Cuban solenodon walking in the dirt.

Cuban solenodons measures up to 22 inches in length and weighs about 3 pounds.

©Emőke Dénes / CC BY-SA 4.0, Wikimedia Commons – Original / License

As the name suggests, the Cuban solenodon makes its home in the island nation of Cuba. It is a nocturnal insectivore that resides in burrows or hollow trees emerging at night to hunt frogs, reptiles, and small rodents. The Cuban solenodon measures around 16 to 22 inches in length, and it typically weighs less than 3 pounds. Predation by feral dogs and habitat loss have damaged this population to the point that it is now an endangered species.

3. Hispaniolan Solenodon

A Hispaniolan solenodon hiding near a rock on the ground.

Hispaniolan solenodons inject venom through their lower incisors that can cause paralysis and death.

©Seb az86556 / CC BY-SA 3.0 – Original / License

A cousin to the previous entry on this list, the Hispaniolan solenodon lives on the island of Hispaniola in both Haiti and the Dominican Republic. Possessing slightly more powerful bite saliva than its Cuban relative, this solenodon preys on reptiles, lizards, and insects. Their bites inject venom through their lower incisors that can cause paralysis and death. Weighing in at just under two pounds, this venomous mammal packs a powerful punch in a small package. Due to its small size, the Hispaniolan solenodon does not normally produce enough venom to threaten a human.

2. Slow Loris

A slow loris near green leaves.

The slow loris possesses sacks beneath its forelimbs that it licks prior to biting, which transfers venom to the mouth.

©hkhtt hj/

The slow loris is arguably the cutest venomous mammal on this list. There are eight species of primate that can collectively be referred to as slow lorises, but they are all distinct species that inhabit Southeast Asia. Endangered by the illegal pet trade, the slow loris is easily captured and smuggled worldwide, and their passive appearance is a defense mechanism to feeling threatened.

The slow loris possesses sacks beneath its forelimbs that it licks prior to biting. Licking the sack transfers venom to the mouth of the loris that can result in an anaphylactic reaction and death. For this reason, smugglers remove the teeth of the slow loris upon capture which sadly results in infection over 90 percent of the time, and death is common.

1. Platypus

A platypus swimming in a body of water.

While not fatal, male platypus venom is unbelievably painful to humans and can result in pain for months.

©Martin Pelanek/

The duck-billed platypus is the most venomous mammal. Its venom is one of the only ones to actually pose a threat to humans. While not fatal, male platypus venom is unbelievably painful to humans, and it can result in lingering pain at the injury site and associated limb for days or even months.

Male platypuses have spurs on their hind legs that can be used to strike when they feel threatened. During mating season, venom sacks grow, and those strikes become truly dangerous as they are now accompanied by a blast of powerful venom. Platypuses are native to Eastern Australia, and they are categorized as a near-threatened species. Read more about the platypus here!

5 Mammals That Use Venom or Chemicals As a Defense

Now we’ve counted down 10 of the most venomous mammals in the world, let’s take a look at a a few other mammals that are not technically venomous but use venom or chemicals as a defense. These animals don’t produce venom themselves but use venom from other animal sources or are mammals that can emit non-venomous but noxious chemicals.


You wouldn’t think such a small, cute animal that can fit in the palm of your hand could be venomous but hedgehogs can be dangerous. While hedgehogs don’t generate venom, they can use venom from other animals as a defense against predators. Wild hedgehogs seek out poisonous toads to kill them and bite into their poison glands or lick and chew on their skin, then spread the poison secreted by the toads onto their spikes by licking them. When faced with a threat, the hedgehog will curl into a ball and use the poison-covered spikes on its back to fend off potential predators.


Skunks are mammals well-known for their ability to release a stinky spray to repel potential threats and predators. This foul-smelling spray is an oil ejected from their anal glands that comprises of a chemical named N-butlymercaptan, which is a mix of sulfur-containing compounds. This chemical is not poisonous but clings to skin or fur and can cause short-term effects in humans including stinging, burning, redness, and tearing of the eyes. Breathing in the spray could cause irritation to the lungs and increase symptoms of asthma. When dogs are exposed to the spray, it can result in drooling, vomiting, getting red or swollen eyes, sneezing, and even becoming temporarily blind. High levels of exposure could potentially lead to damage of red blood cells in dogs, but this is very rare.

Striped Polecat

Similar in appearance and defensive behavior to a skunk, this mammal uses a spray against potential predators. This noxious spray is also released from its anal stink glands and has much of the same effect, with possible effects of exposure being temporary blindness and irritation of the mucous membranes that leads to a strong burning sensation.


Sometimes known as the scaly anteater, this mammal is distinguished by its large keratin scales covering its skin and forming a protective layer. Apart from this defense against potential threats, the pangolin has other ways of deterring predators: curling into a ball and releasing a noxious chemical from the glands close to its anus, much like a skunk except not in a spray form.

Greater Long-Nosed Armadillo

What Eats Snakes

Hedgehogs can cover their spikes with poison from toads to fend off potential predators.


Another mammal known for its tough armor-plated exterior of keratin scales, the armadillo is well-equipped to defend itself. The greater long-nosed armadillo is a South American species of armadillo that has an extra line of defense: when threatened, it emits an unpleasant odor of musk.

Summary of the World’s Most Venomous Mammals

Let’s recap the mammals are the most venomous on Earth.

RankMammalPoison Location
1PlatypusHind leg spurs
2Slow LorisForelimb sacs
3Hispaniolan SolenodonSaliva
4Cuban SolenodonSaliva
5European MoleSaliva
6Short-Tailed ShrewsSaliva
7Mediterranean Water ShrewSaliva
8Eurasian Water ShrewSaliva
9Vampire BatsSaliva
10Maned RatPoison-coated hair

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About the Author

I'm a freelance writer and editor with over 10 years of experience. I'm a proud dog owner; we often go on hikes and adventures in the mountains to appreciate nature. I relish writing articles on pets that are informative and entertaining. Moreover, I enjoy traveling, reading, and writing for fun when I'm not working.

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