Bats readily roost in buildings, seeking out areas which suit their needs at different times of the year.  Some species require open areas in lofts or barns for at least part of the year as they fly around within the roost before and after dusk.  When behaving like this bats may be visible in the loft and their droppings are likely to be found on the floor or surfaces.  Bats may also retreat above ridge boards or behind felt or board lining so may not be visible at all. 

Some species are less likely to be seen as they prefer smaller cavities, for example beneath tiles or slates on a roof.  Bats also use cavity walls, soffit boxes, holes or splits in roofing timbers (often at joints), the gap beneath ridge tiles, behind hanging tiles and sometimes under lead flashing.  If a chimney is unused for some time then bats may roost inside; cellars may also be used.

All kinds of buildings may be used including old and modern styles, outbuildings, barns (particularly stone barns and barns with old wooden beams) and ice houses.  Bats also roost in tunnels, bridges (both old and modern), caves and mines, historic buildings such as castles and pill boxes.

Normally a daytime search is complemented by evening and/or dawn surveys to watch for bats and listen with bat detectors.  Sometimes other methods may be required with video monitoring, night vision and long-term automated bat detectors offering additional survey options. 

Scroll through the photographs below to see a range bat roost sites in buildings.