All 18 UK bat species are protected by law, with roost disturbance causing significant welfare harm to one of Britain's most important nocturnal wildlife groups.
Bats disturbed from maternity roosts abandon pups that cannot thermoregulate independently, causing death from hypothermia. Adults disturbed during hibernation deplete fat reserves prematurely, risking starvation before spring. Building works that destroy roosts kill roosting bats directly. Chemical timber treatments in roof spaces were a major historic cause of bat mortality. Modern roost surveys before building works prevent roost destruction and protect individual bats.