Bats in Buildings

Several of our Bat species have adapted to make use of man-made structures, often without us being aware of their presence. Unlike rats and mice, roosting bats do not roam a building in search of food and do minimal damage to the building, unless they roost in particularly large numbers, when smell and droppings can become an issue.

Crevice-loving species, such as Soprano Pipistrelles (Pipistrellus pygmaeus) and Common Pipistrelles (P. pipistrellus) are often found roosting in modern buildings. Cavity walls, and the narrow spaces between roof tiles or slates and sarking or lining below, provide perfect roosting spaces, often accessed through small gaps behind soffits (a gap of just 10mm is sufficient).

Brown Long-eared Bats (Plecotus auritus) like open attic-spaces, usually in older buildings. They often roost in the apex of the roof or in the gap between rafters and a wall. Natterer's Bats (Myotis nattereri) also tend to use old, stone-walled buildings and often roost in stone wall crevices or gaps in beam joints.

Daubenton's Bats (Myotis daubentonii) usually roost close to water and tend to seek holes and crevices in stone or concrete-built structures, such as bridges.

Each bat colony will use a variety of different roosts for different purposes and at different times of the year. If bats appear to have left it does not mean they will not return.

Cellars or tunnels may be used in winter by hibernating bats, especially Daubenton’s, Natterer’s and Whiskered Bats (Myotis mystacinus), which seek places with a steady cool temperature and high humidity. Pipistrelles and Brown Long-eared Bats hibernate in crevices in buildings and elsewhere.

All bat roosts are legally protected, whether or not bats are present. Disturbing or destroying a roost is a criminal offence, unless a derogation license is first obtained. Ignorance of their presence is no defence if a bat survey has not been carried out.