Shrew: animal profile, types & venomosity
Often confused with other small mammals, the shrew is not actually a rodent but more closely related to the hedgehog and mole. Discover all about the shrew.
Widespread throughout mainland Britain, the shrew (Soricidae) is one of our most common native mammals. As a key part of our ecosystems, shrews are protected here under the Wildlife and Countryside Act of 1981. Keep reading to learn more about the different types of shrews as well as their diets and habitats.
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Shrew: size, habitat, diet and more
Containing around 350 different species, the shrew family is extensive. However, here in mainland Britain, you are only likely to come across one of the three British shrew types. Commonly mistaken with our other small furry friends, the shrew is not actually a rodent but more closely related to moles (Talpa europaea). However, unlike mice (Muridae), you can identify shrews by their long and pointed noses and short limbs. They are also typically smaller than mice, and depending on the type of shrew, their sizes range from 4 to 8cm long.
Although found almost everywhere, shrews tend to favour hedgerows, grassland and woodland. They are frequently found foraging along the ground but sleep in burrows, often formed by another animal, a few inches below the surface. The shrew’s lifespan is around 1 year, but they can live for longer where predators are scarce.
As an insectivore, the shrew’s diet generally consists of earthworms (Lumbricus terrestris), spiders (Arachnida), slugs and snails (Gastropoda). They have a fast metabolism, and in order to survive, they need to eat every 2 to 3 hours and consume around 80% of their body weight daily. With their tiny eyes, shrews are often thought of as blind. However, even though they are not completely blind, they do have poor eyesight, which they make up for with their excellent hearing, smell and touch.
What is the difference between shrews, mice, voles and moles?
When it comes to distinguishing shrews from mice, moles and voles (Cricetidae), there are some key differences between them. Being larger than shrews, moles can grow to 13 to 16cm long and are easily recognised by their spade-like front paws. Mice and voles also tend to be larger than shrews and can be identified by their larger eyes and ears and shorter noses. Interestingly, only mice and voles are considered rodents, with shrews and moles classified as insectivores.
Types of shrews
With such a large family, there are many different types of shrews. Adapted for different climates and habitats, here are some of the different shrew types:
British shrews
The shews you may find in the UK comprise of three different types, with the aptly named common shrew (Sorex araneus) being the most likely.
Common shrew
The common shrew is the most prevalent shrew and the most likely to be found in the garden. Growing to around 5 to 6cm long, the common shrew has a long tail that can reach 3 to 5.5cm in length. The top and sides of its body are generally dark brown, in contrast to its lighter grey underneath. Present everywhere but prefers woodland or grassed areas. Weighs 5 to 14g.
Pygmy shrew
Similar in colour to the common shrew, the pygmy shrew (Sorex minutus) grows to around 4 to 6cm long and develops a long, thick tail up to 5cm in length. However, it has a shorter and narrower nose compared to the common shrew. Prevalent in most habitats and very territorial. Weighs 2 to 6g.
Water shrew
Favouring wetlands, the water shrew (Neomys fodiens) is the largest of British shrews. Its body grows to 6 to 9.5cm long with a long tail up to 8cm in length. As a proficient swimmer, it can be found in ponds, streams and other wetlands. Darker in colour, you can identify it by its black or dark grey body and white underside. Weighs 12 to 18g.
Other types
Here are some other types of shrews that you might come across outside of the UK:
Elephant shrew
Found in Africa, elephant shrews (Macroscelidea) comprise around 20 species and range in colour from tan-brown to black. Slim-bodied and with long hind legs, elephant shrews are not classified as shrews but are thought to be more closely related to the elephant. Featuring large eyes and ears, the weight of elephant shrews can range from 30 to 700g. Inhabiting parts of Africa, they prefer sandy, rocky or dry woodland habitats.
Etruscan pygmy shrew
Also known as the Etruscan shrew (Suncus etruscus), this smallest type of shew is found from the Mediterranean to Southeast Asia. Growing from 35 to 48mm long, it weighs a mere 1.3 to 2.5g. Grey-brown in colour, the head of the Etruscan pygmy shrew is relatively large in comparison to the size of its body. Living alone except during the mating season, they tend to be infrequently seen.
Northern shrew
Found in the north-eastern region of North America, the northern shrew (Blarina brevicauda), or northern short-tailed shrew as it is also known, is the largest shrew of the Blarina genus. Weighing up to 30g, it can grow to a length of 14cm including its short tail. Dark grey to black fur covers its back, with a lighter shade underneath. As a venomous shrew, its saliva delivers poison into the bite wound of its prey immobilising them. They are identifiable by their red teeth and are also insectivores. Favouring hedgerows, woodland and river banks, this type of shrew is very active.
Shrews in the house and garden
Being fond of hedgerows and grassland, you may find shrews amongst rows of shrubs or grassed areas in your garden. You might also find them amongst or near piles of leaves and compost heaps. As active and hungry mammals, they are often on the hunt for food, underground or in the open.
Although unusual, shrews can find their way inside your home, especially at basement level. Entering through gaps and holes in the walls, shrews may be tempted by any insects residing inside to feed upon. If identified, shrews should not be approached, as they may become aggressive, but rather captured humanely using a live trap before being removed.
Are shrews venomous?
If you are wondering if shrews are venomous, the answer is that they can be. Here in the UK, only the water shrew is venomous and is in fact our only venomous mammal. As with the northern shrew, its saliva contains a poison that immobilises its invertebrate prey. If humans are bitten, the venom may cause discomfort and irritation to the skin for some time.
How to get rid of shrews
If you discover a shrew in your house, you can either trap it humanely or arrange for pest control to remove it for you. Due to their need to eat every few hours, a bait of worms or slugs can prove effective. When laid, check the trap frequently, and if captured, any shrew should be released quickly, either back into the garden or further afield. To help prevent shrews from coming inside in the first place, block any holes or gaps. Since shrews may carry diseases and parasites, any direct contact with them is inadvisable.
Even though dissimilar in looks, the shrew is related to the hedgehog (Erinaceus europaeus). Read more about hedgehogs and other beneficial garden animals here in our other article.
