Are there any animals more weird and wonderful than bats? They are the only mammals that can fly, they sleep upside down, use echolocation to get around and have inspired fear and fascination in humans for centuries. Here’s everything you need to know about these amazing creatures.

Bat basics

The UK is home to 18 species of bat, ranging from the common pipistrelle, which has a population of around 2.4 million, to the greater mouse-eared bat, which numbers just one solitary male in southern England.

Bats are surprisingly small creatures. Our largest species – the noctule – weighs no more than 40 grams, while a common pipistrelle may weigh as little as 3 grams – that’s less than a 1p coin!

All of the UK’s species are insectivores, meaning their diet is made up of insects like moths, flies, beetles and mosquitoes. With one bat capable of eating thousands of insects each night, they play a key role in our environment.

Eight of the UK’s bats are considered indicator species, meaning changes in their numbers are used as a gauge for measuring biodiversity as a whole.

Where do bats live?

Bats can occupy a wide range of habitats, with variation depending on the species and time of year. All of our bats are nocturnal and spend the day sleeping in safe, sheltered spots known as roosts. In the winter, bats enter hibernation and will typically sleep from November through to April.

Our bats evolved to roost in natural features such as caves and holes in trees. But they quickly adapted to the man-made environment and will readily roost in the roofs of buildings such as houses, barns and churches or under bridges and in mines. Using these man-made features has been crucial for bats' survival, as natural roost sites, like ancient trees, have become increasingly rare.

All of our bat species use woods, but six species can be considered woodland specialists: Bechstein's, barbastelle, Natterer's, noctule, lesser horseshoe and brown long-eared.

Ancient woods and trees are of particular value to bats as they support higher numbers of insects and large mature trees have more holes, cracks and crevices for roosting. Half of our ancient woods have been lost or damaged since the 1930s and protecting those we have left is important for the conservation of our bat species, as well as other wildlife.

Super sonar: echolocation

When it comes to getting around, bats take a remarkable approach: a form of biological sonar known as echolocation. As they fly, bats make high frequency calls that are inaudible to the human ear. By listening to the echoes these calls make, bats are able to build a map of their surroundings and locate their prey. Echolocation is not a compensation for blindness – bats can see almost as well as humans – it is simply a far more effective way of flying around and catching small insects in the dark of night.

Bats will also use linear features such as hedgerows and tree lines to move around. By travelling alongside these features they are less vulnerable to predators, like birds of prey, than if they were flying out in the open.

Types of UK bat


Pipistrelles are our most common type of bat. The common pipistrelle and soprano pipistrelle were considered the same species until 1999 and their combined population numbers roughly 3.7 million. Both species are often found in urban areas and are easily the bat you're most likely to see.

Much rarer is the Nathusius’ pipistrelle. Originally thought to be just a migrant visitor, there is now an estimated population of around 16,000, with a significant number in Northern Ireland.


As the name suggests, long-eared bats are distinguishable by their huge ears, which are nearly as long as their body. This allows the bats to better hear their insect prey, rather than relying on echolocation alone.

There are two species - the grey and the brown – with the latter found across the UK. The grey long-eared bat is much rarer, with a population of only around 1,000 restricted to southern England.


These species are named after their horseshoe-shaped noses, which help to focus their echolocation calls. The lesser horseshoe bat has a population of around 50,000 concentrated in South West England and Wales. The much larger greater horseshoe is rare, with a population of less than 7,000 found mainly in the South West.

Other bats

Other species found in the UK include Daubenton's bat, which swoops low over rivers, canals and other water sources to catch aquatic insects, and Brandt's bat, which have been known to live for more than 40 years in some parts of the world. The greater mouse-eared bat was declared extinct in the UK in 1990, until the discovery of a solitary male that has been hibernating here since 2002.

The noctule bat is our largest bat and often roosts and hibernates within holes in trees, while the serotine bat is usually one of the first bats to emerge in the evening and commonly flies at tree-top level while hunting.

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