Common and soprano pipistrelle bats use buildings as maternity roosts where females gather to give birth and raise pups. Maternity roosts require legal protection and sensitive management during the critical May to August period.
Pipistrelle pups that lose their maternity roost during the critical development period cannot survive. Females attempting to retrieve displaced pups from damaged roosts expose themselves and their young to cold. Roosts that are treated with pesticides cause toxicological harm to bats through contact and inhalation. The welfare harm of roost disturbance during maternity season is severe and affects both pups that die and adults that must find alternative unsuitable roosting locations.