The most common bat in Britain is the pipistrelle. It is also one of the smallest bats at just 5 cm long , a wingspan of 20cm and a weight of 4 grammes. One of the largest British is the noctule. It is 8 cm long and can often be mistaken for a swift. Pesticides, chemicals which kill their prey.
Bats roost in roofs.
The timber in the roofs are treated with chemicals which poison the bats. The Forest of Leeds Organisation has been putting up bat boxes in the woodlands it looks after. These boxes are made of wood and attached to trees high off the ground. They provide roosting sites for the bats and help to make up for the decline in natural sites. It is important that these boxes are in woods because much of the bats food is found in this habitat.