Hispaniolan Solenodon
Credit: Wikipedia photo by Seb az86556, CC BY-SA 3.0.

The Hispaniolan solenodon is one of two species of solenodon in the world.[1] Discussed below, they are the most venomous mammals, approaching the toxicity of typical venomous snakes.[1]

Some mammals are known to have venom

When someone thinks of a venomous animal, they’re probably going to think of snakes, arachnids, wasps, or perhaps jellyfishes, but not mammals.

There are some mammals known to have venom, although the definition of “venomous,” with regards to mammals or animals in general, is subject to debate.[2] For this article, we’ll include any mammal with at least one venom gland, and an ability to intentionally inject another animal with that venom.

The definition of venom, according to dictionary.com, is: “The poisonous fluid that some animals, as certain snakes and spiders, secrete and introduce into the bodies of their victims by biting, stinging, etc.”

Australia's platypus

Credit: From Wikipedia by Klaus, CC BY-SA 2.0.

The platypus lives in Tasmania and in Eastern Australia. They are small, with total length including tail averaging 20 inches (51 cm) for males, and 17 inches (43 cm) for females.[3]

What most people know as the weirdest mammal in existence, with its duck-like bill and beaver-like tail, these mammals are part of an ancient group called monotremes, the only others of which are four species of echidna. Monotremes are the only mammals that lay eggs, and male platypuses have a venomous spur on each hind limb.[3]

The venomous spurs are used not just for defense, but for fighting over females during mating season. The venom is not powerful enough to kill a human, but it can cause excruciating pain.[3]

Two species of loris in Southeast Asia

Pygmy Slow Loris
Credit: From Wikipedia by David Haring, CC BY-SA 3.0.

The pygmy slow loris lives in Southeast Asia in Vietnam, Laos, Cambodia, and a small portion of China.[4]

Lorises are a family of primates found in Asia, and there are ten species.[5] Two of the species, the slow loris and the pygmy slow loris, have venom glands near their elbows.[2]

The venom is licked, and then it can be injected into some of their prey when they bite. The venom is only harmful to certain animal species.[2]

Some scientists say they shouldn’t count as venomous animals because the venom gland and the point of venom injection are separate from one another,[2] although others disagree. 

The European mole

European Mole
Credit: From Wikipedia by Didier Descouens, CC BY-SA 4.0.

The European mole prefers to burrow through moist soil - not too wet or too dry.[6]

Spending most of their lives in underground tunnel systems that they create, these five-inch (12 cm) mammals live all through the central part of Europe, and also Great Britain. Their favorite food, preferred over anything else, is earthworms.[6]

Their saliva contains toxins that paralyze earthworms. This allows them to store earthworms for later consumption, as the worms stay alive but in a paralyzed state until the mole needs a meal.[2]

It is thought that other mole species may possess this ability as well, although it hasn’t been confirmed.

Three species of shrew

Northern Short-tailed Shrew
Credit: From Wikipedia by Gilles Gonthier, CC BY 2.0.

The Northern short-tailed shrew lives throughout much of the eastern half of North America.[8]

Shrews are small mammals related to moles. Although they resemble rodents, they are a separate lineage.  They belong to the taxonomic family Soricidae and can easily be confused with other mammals in different orders with “shrew” as part of the name such as West Indies shrews, treeshrews, otter shrews, and elephant shrews.[7]

True shrews, as they're called, are found on all continents except Australia and Antarctica. Of all families of mammals, they are surpassed in numbers of species only by two families of rodent, and one family of bat.[7]

Out of nearly 400 species, three are known to be venomous. They are the Northern short-tailed shrew of North America, the Mediterranean water shrew of Europe, and the Eurasian water shrew of Europe and Asia.[2]

Like the European mole, their venom immobilizes their prey and keeps them alive for storage purposes until the shrew wants to eat. They do this to earthworms, snails, insects, and mammals smaller than themselves, such as mice.[7]

There may be other shrew species that are venomous, although it hasn’t been confirmed.[2]

Solenodons of Cuba and Hispaniola

Cuban Solenodon
Credit: From Wikipedia and in the public domain.

The Cuban solenodon is very rarely seen by humans.[9]

Solenodons look like large shrews, although are part of a separate taxonomic family within the same order. There are only two living species.[2][1]

The Cuban solenodon lives in the far eastern portion of the island of Cuba, and is an endangered species that is rarely seen by humans.[9]

The Hispaniolan solenodon, in the photo at the top of the article, lives on the island of Hispaniola, which is divided approximately in half between the nations of Haiti and the Dominican Republic. They are also an endangered species, and are also rarely seen by humans.[10]

Mostly they burrow in the ground, similar to shrews and moles. Each has a venomous bite, with venom much more powerful than that of the shrews discussed above. It has been observed that their bites will kill mice, for example. This makes their venom more like that of venomous snakes.[1][2][9][10]

Symptoms for humans of having been bitten by a solenodon can include general depression, difficulty breathing, and even paralysis and convulsions.[1]

Mammals that deliberately put poison on themselves

African Crested Rat
Credit: From Wikipedia by Kevin Deacon, CC BY-SA 3.0.

The African crested rat is not venomous, although covers its back with a toxic mixture powerful enough to kill many predators who would try to take a bite.[13]

Three mammal species are known to deliberately place poison on their backs. Hedgehogs and tenrecs, which look similar to one another, although are from different lineages, will find poisonous toads, bite into the poison glands, and then smear it onto the spines on their backs.[2]

Hedgehogs live all through Asia, Europe, and Africa.[11] Tenrecs live in Africa and on the island of Madagascar.[12]

One species of rodent, the African crested rat, does something similar with poison from a plant called the poison-arrow tree. It chews the plant and then places the mixture on its back. This plant is so poisonous that it was used traditionally to make arrows with poison tips that can kill elephants. The rat uses this poison so any predators who try to take a bite become seriously ill or actually die.[2]

This rat species is found in Eastern Africa from Sudan to Tanzania.[13] If you ever see one, now you know not to touch it.