Venomous Mammals: From Shrews to the Platypus
Disclosure: Some links may be affiliate links. If you buy an item via links on our site, we may earn a commission. Learn more.
If you thought that it was only animals that slither, crawl, and skitter that were venomous; think again. Did you know that there are several venomous mammals in the world and while they might look sweet and innocent, they can really pack a punch!
Examples of Venomous Mammals
Mammals aren’t usually venomous and will typically defend themselves and catch prey using other methods. However, there are some that possess venom glands, such as various types of bats as well as things like the platypus and certain types of shrews.
Venomous Platypus
Many say that the platypus is the most obscure mammal in the world. It certainly has a unique appearance, but what also sets it apart from its mammalian cousins is its venom. Let’s find out more.
Platypus (Ornithorhynchus anatinus)
The duck-billed platypus is a species of monotreme, and unlike other mammals, does not give birth to live young but instead, lays eggs. These animals are not widely distributed and are found only in wetter regions of Tasmania and eastern Australia, where they’ll be found in rivers, streams, and, lagoons with a lot of vegetation along the banks.
The platypus is venomous and has sharp spikes on its hind feet which it uses to give a nasty surprise to anything that tries to attack it. While the male has the ability to squirt venom from this sharp point on the foot, females lose this spur during their development. There is the suggestion that males will also use their spurs as a way of fighting off rivals during mating season.
The venom of the platypus could be potent enough to kill small animals. However, it’s not usually lethal to humans. That said, in controlled studies, it has been noted that humans stung by a platypus experience immediate severe pain and may temporarily lose function in the affected area. While not a lot is known about platypus venom, scientists have recently found out that a compound known as heptapeptide 1 is likely responsible for the excruciating pain of a sting.
Venomous Bats
Bats are a type of flying mammal, and they’ve already got something of a bad reputation before people realize that some of them are venomous!
Vampire bats especially get a bad rap, and there are rumors that they’ll feed on human blood. However, while they do bite for blood, this is usually reserved for things like cattle. Still, you might want to keep away from the following species if you don’t want to be envenomated.
Hairy-Legged Vampire Bat (Diphylla ecaudata)
The hairy-legged vampire bat can be found in the tropical forests of South and Central America. Compared to the common vampire bat, this species has much shorter ears and very distinct large eyes. These eyes give the bat some impressive eyesight, although its echolocation abilities are poor compared to other species.
They typically feed on the blood of wild birds and are nocturnal animals that spend most of the daytime hiding out in caves.
So what about venom? Well, the hairy-legged vampire bat actually produces a toxin known as draculin in its saliva. This aids the bat when feeding in two ways; the toxin acts as an anesthetic as well as preventing the victim’s blood from clotting.
White-Winged Vampire Bat (Diaemus youngi)
Another species of vampire bat that is able to produce toxins is the white-winged vampire bat. These bats are generally found in tropical forests in South America and much like their hairy-legged cousins will spend most of the day roosting in caves.
As with other species of vampire bats, the white-winged vampire bats feed solely on blood. This is a diet known as hematophagy, and the bat will pinpoint an area on its victim where the blood runs close to the surface before piercing it with sharp teeth.
Plasminogen activators in the bat’s saliva stop the animal’s blood from clotting as the bat feeds, as well as platelet aggregation inhibitors that prevent further clots from occurring. These toxins are very effective on birds which are often one of the white-winged vampire bat’s favorite victims.
Common Vampire Bat (Desmodus rotundus)
The common vampire bat is another South and Central American species that live in both dry and moist tropical and subtropical areas. They’ll hide in tree hollows, rock fissures, and caves and may live in colonies, some of which have thousands of individuals.
Common vampire bats have compounds within their saliva that can cause their victim’s blood vessels to dilate. While they may feed on a variety of animals’ blood, they usually prey on things like pigs, horses, cows, and tapirs.
But there’s no need for humans to be concerned because it’s incredibly rare that these bats or any other vampire bat species would prey on us. That said, if they did, while the bite wouldn’t necessarily be painful, the bat may carry infections that could be passed on to humans, such as rabies. However, with vaccinations, the number of people that die from this viral disease in North America is no more than two per year.
Venomous Solenodons
You may not be familiar with the solenodon as some species, such as the Hispanic solenodon, are considered to be critically endangered. Closely related to the giant African shrew, solenodons are unusual creatures that have venom glands in the mouth, a trait that is thought to have been common in many ancient mammals. However, since it’s believed that the solenodon has remained largely unevolved for the last 76 million years, it has retained this characteristic.
Cuban Solenodon (Atopogale cubana)
The Cuban solenodon can be found only in mountainous areas of Cuba and rarely comes into contact with humans. This is largely because these are nocturnal mammals but also because of their burrowing habits that keep them concealed during the day.
Cuban solenodons mainly prey on insects, which they immobilize using the venom glands located in their lower jaws. What’s interesting is that this venom can also be used to affect other Cuban solenodons as, in studies, cage mates have been killed after fighting with one of their own.
While the venom is not fatal to humans, it is enough to immobilize larger prey such as amphibians and birds, so the solenodon is capable of taking down a pretty sizable meal!
Hispaniolan Solenodon (Solenodon paradoxes)
For a long time, it was thought that this elusive animal was extinct. We now know that while some species of solenodon have died out, the Hispaniolan solenodon survived, although it is critically endangered. It is found only on the island of Hispaniola in the Caribbean Islands.
Just like Cuban solenodons, this species has venom glands in the lower jaw. They’re the only mammals that can inject venom using their teeth in a similar manner to snakes. It’s thought that the animal uses this venom not only to immobilize its prey but also to aid with digestion and reduce how much energy the solenodon needs when taking down larger prey.
Venomous Moles
Moles aren’t usually seen as dangerous animals. If anything, they are seen as quiet, solitary creatures that only cause problems with their little molehills. But what a lot of people don’t realize is that a certain species of mole uses toxins in order to catch prey.
European Mole (Talpa europaea)
Sometimes called the common or northern mole, the European mole can be found in northern parts of Europe, including Russia and the United Kingdom. They live underground for most of their lives and only really come up to the surface accidentally. You’ll find these little creatures living in soils below arable fields, in woodlands and pastures.
Just like the bats we talked about earlier, the European mole has toxins within its saliva, and these are used to immobilize the earthworms on which the animal feeds. However, where there is not a decent population of earthworms, the mole will also prey on insects and their larva.
European moles are very standoffish and won’t attack humans without being provoked. What’s more, while they have sharp teeth, their toxic saliva isn’t dangerous to humans. Still, it’s best to avoid being bitten.
Venomous Shrews
Shrews are small, super-fast, and excellent predators. While you might not see them very often due to how skittish they are, they’re one of the most common mammals in the United States. There are 385 species of shrews, with many being venomous.
Northern Short-Tailed Shrew (Blarina brevicauda)
The Northern short-tailed shrew is one of the most common mammals in the United States. It’s typically found in the northeastern parts of the USA but is also common in Canada.
Growing no more than around 5 inches (12.7 cm) and weighing just an ounce (28 grams), these are tiny creatures, but their bite packs a punch as their saliva is bursting with toxins. This kallikrein-like protease paralyzes the shrew’s prey, eventually killing it. However, the venom is not fatal to humans, but if you are bitten, it’ll surely be painful thanks to those sharp teeth!
Mediterranean Water Shrew (Neomys anomalus)
The Mediterranean water shrew is found in parts of southern Europe, including Albania, Greece, Macedonia, Turkey, Portugal, and France, as well as in Iran, moving further east.
While they might be small, these shrews consume a lot of food; up to three times their own body mass each day in order to avoid losing body heat. They typically prey on small fish, amphibians, and a variety of insects.
They have a toxic venom in their saliva that is designed to kill their prey, with the Mediterranean water shrew being able to finish off a fish in minutes. However, while the bite may be painful to humans, the venom won’t cause any adverse effects.
Eurasian Water Shrew (Neomys fodiens)
Preferring areas along flowing fresh water, the Eurasian water shrew can be found from Siberia to Korea as well as in parts of Europe such as the United Kingdom, where it’s simply referred to as the water shrew.
These dark-colored shrews mainly hunt for prey under the water, looking for things like aquatic snails, fish, mollusks, and amphibians. However, because of the hemolytic action of the venom, it’s thought that they’re able to take down much larger prey.
Solitary animals, these shrews not only use their venom to catch prey but also to immobilize it so they can store it for later. This is common in many types of shrews. To humans, the venom has no effect.
Southern Short-Tailed Shrew (Blarina carolinensis)
The southern short-tailed shrew is common in the southeastern parts of the United States. Again, these are small animals, and they don’t grow much larger than 5 inches (12.7 cm) in length. They are typically found in well-drained areas where the soil is ideal for burrowing.
Southern short-tailed shrews are pretty ballsy when it comes to humans, and it’s not uncommon to see them entering the home. Again the toxins in their saliva won’t do much harm to a human, but the bite itself can be painful.
They’ll use their toxic saliva to finish off their prey before chowing down. The diet of the southern short-tailed shrew is varied and may include things like spiders, snails, and centipedes. But it’ll also sometimes feed on fungi.
Everglades Short-Tailed Shrew (Blarina peninsulae)
Native to the southern parts of the United States, most notably Florida, the Everglades short-tailed shrew is a tiny creature that only gets to between 3 and 5 inches (7.6 and 12.7 cm) and weighs just half an ounce (14 grams).
But just because it’s small, that doesn’t mean it’s not mighty, and these shrews can bring down large prey thanks to their toxic saliva. Again, as with most other types of shrew, the Everglades short-tailed shrew’s venom won’t cause any problems to humans. It’s the teeth that you want to worry about because they can deliver a painfully unpleasant bite!
Elliot’s Short-Tailed Shrew (Blarina hylophaga)
Elliot’s short-tailed shrews are found across central parts of North America, including Kansas, Texas, Iowa, Arkansas, and Missouri. They weigh just half an ounce but can grow up to 5 inches (12.7 cm) in length.
However, while they are small, Elliot’s short-tailed shrews aren’t averse to taking down large prey, including mice. That said, they will also feed on smaller things like insects, but in any case, the toxins in their saliva are designed to make any prey they bite a fatality.
But don’t worry, if you ever come into contact with one and it bites you, the venomous saliva won’t cause you any harm. Although the bite will probably cause some localized pain.
Transcaucasian Water Shrew (Neomys teres)
As with many other types of shrews, the Transcaucasian water shrew uses a toxin in its saliva to paralyze and kill its prey. They’re very similar to the Eurasian water shrew but are not as widespread. This particular species is only found in Turkey, Azerbaijan, Armenia, and Georgia, and there are some reports of sightings in Iran.
Venomous Loris
Lorises might look sweet and innocent with those big eyes and all that fuzzy fur, but they’re another of the venomous mammals in the world. However, unlike things like shrews, the venom of these cute creatures could cause problems for you and me.
Slow Loris (Nycticebus spp.)
The slow loris is broken down into eight subspecies and these are found across southeast Asia from the northern parts of India to the Philippines.
While many venomous mammals use either gland in the mouth or their saliva to envenomate their prey, the slow loris does things a little differently. Their venom glands are located under their arms, near their elbows, so if you ever see one raising its arms, it might not be asking for a hug!
The venom must be mixed with the slow loris’ saliva in order to activate it. The animal will lick its brachial glands and then use toothcombs to distribute it. There is some suggestion that this isn’t actually a venom but more of an allergen that could be similar to cat allergens. But in any case, the slow loris has been dubbed the only venomous primate in the world.
The venom is used as a defense mechanism, but it’s fortunately not fatal to humans. That said, it is known to cause pain and swelling so it’s best to keep at arm’s length and admire these beautiful creatures from afar.
Why are there so Few Venomous Mammals?
When most of us think of venomous animals, we imagine things like spiders, snakes, and even types of venomous fish, like the stonefish. While there are venomous mammals, they’re nowhere near as abundant, and this raises the question as to why?
A lot of it has to do with evolution and surprisingly, it’s thought that venomous mammals and reptiles have a common ancestor somewhere in the past. On top of this, scientists believe that any animal with a saliva gland has the potential to evolve to be venomous because of how these glands work.
But the thing with mammals is that they’re already well-equipped to catch prey and defend themselves in ways that other animals may not be. For example, mammals have sharp teeth and claws that allow them to fight. Using venom is a much slower method and, according to researchers, is far less effective, therefore fewer mammals developed this trait.
