The World’s 10 Most Venomous Mammals

Written by AZ Animals Staff
Published: February 14, 2021

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 ten most venomous mammals!

#10: Maned Rat

The maned rat holds the last 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.

A maned rat walking on the ground near a tree root.
The maned rat, while not technically venomous, rubs its back in poisonous tree sap, and unsuspecting predators get a mouthful when they attack.

#9: Vampire Bats

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.

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. Check out more interesting facts about the Central and South American vampire bat species here.

A vampire bat with its mouth open on the side of a rock.
While a vampire bat’s venom does not cause pain or paralysis, it coagulates the blood of its prey so the vampire bat can feed more freely.

#8: Eurasian Water Shrew

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 two to four inches in length, this tiny mammal should still be handled with protective gloves.

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.

#7: Mediterranean Water Shrew

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 three inches and weighs under half an ounce.

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.

#6: Short-Tailed Shrews

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 five inches long and weigh under one 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 three to five inches in length, but they weigh approximately three ounces. That’s much heavier than their cousins.

These animals all have a conservation status of least concern.

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 which paralyzes prey.

#5: European Mole

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 four and six inches with a tail that adds another inch, and they weigh about three to five 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.

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.

#4: Cuban Solenodon

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 three pounds. Predation by feral dogs and habitat loss have damaged this population to the point that it is now an endangered species.

A Cuban solenodon walking in the dirt.
Cuban solenodons measures up to 22 inches in length and weighs about 3 pounds.

#3: Hispaniolan Solenodon

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.

A Hispaniolan solenodon hiding near a rock on the ground.
Hispaniolan solenodons inject venom through their lower incisors that can cause paralysis and death.

#2: Slow Loris

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.

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.

#1: Platypus

The duck-billed platypus are 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!

A platypus swimming in a body of water.
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 months.

Venomous Mammals List

  1. Platypus
  2. Slow Loris
  3. Hispaniolan Solenodon
  4. Cuban Solenodon
  5. European Mole
  6. Short-Tailed Shrews
  7. Mediterranean Water Shrew
  8. Eurasian Water Shrew
  9. Vampire Bats
  10. Maned Rat