Pipistrellus is a genus of bats in the family Vespertilionidae and subfamily Vespertilioninae. The name of the genus is derived
from the Italian word Pipistrello, meaning "bat". The size of the genus has been considerably reduced as a result of work
during the 1990s and 2000s, with genera like Arielulus, Hypsugo, Falsistrellus, Neoromicia, Parastrellus, Perimyotis, Scotozous
and Vespadelus being split off. Still, molecular evidence suggests that the genus is not monophyletic.