Night time light pollution is rapidly increasing across the world. Nocturnal animals are likely to be especially affected but how they respond to artificial light is still largely unknown. In a new study, scientists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) in Berlin, Germany, tested the response of European bats to red and white light sources during their seasonal migration. Soprano pipistrelles (Pipistrellus pygmaeus) and, to a lesser degree, Nathusius’ pipistrelles (Pipistrellus nathusii) were recorded more frequently near red LED light, indicating that the animals might be attracted to red light during their migration. In contrast, the scientists did not observe such behaviour near white LED lights.