If you’re out in your garden at dusk or later in the evening, you may catch a glimpse of a flying mammal out of the corner of your eye. While you can sometimes spot them in the daytime, bats are mostly nocturnal creatures that hunt during the night.

There are 18 species of bat in the UK, but two of the most common species you might see in your garden are the common pipistrelle and the brown long-eared bat. Recognised as biodiversity indicators, their presence suggests a healthy, insect-rich environment.

Their ears are more important at night

Their diet is made up of moths, flies, beetles, lacewings and other nocturnal insects, and they use echo location to find their prey. Contrary to the common myth that bats are blind, different species have varying visual abilities, but their ears are more important at night than their eyes.

They make clicking sounds as they fly, and their incredible hearing helps them to listen for echoes of this sound that bounce off insects, walls and other predators. You are very unlikely to hear the echolocation calls, as the frequency is often too high for human ears.

Bats usually roost in buildings, trees or bat boxes, and are often spotted swooping around parks, gardens, woodlands and farms. They can also be found near bodies of water, in part to quench their thirst, but they also forage on insects with aquatic larvae.

Pregnant females gather in large numbers ready to give birth

At this time of year, pregnant female bats start to form maternity roosts, where they gather in large numbers ready to give birth. They usually have a single pup that stays with them for about a month, feeding on their milk, until the pup is old enough to forage for itself.

Despite being a valuable part of UK nature, bat numbers are declining at a rapid rate. There are, however, things we can do to help. Consider adding a pond to your garden and make sure your green space is a thriving, insect-rich feeding ground. Linear features such as streams and hedges are also important, as they act as navigation pathways that bats use as they travel between their shelter and feeding sites.

You must leave loft-roosting bats alone

Bat boxes can be purchased from garden centres and placed in sunny southerly or westerly locations to provide a warm, sheltered place for them to rest. If you happen to find a bat roosting in your loft, you must leave it be – bats and their roosts are protected by law and waking them from hibernation at the wrong time of year can use up valuable fat stores that they need to get them through the winter.

Be sure to consult a wildlife organisation or your local authorities before carrying out loft repairs or renovations.