Common pipistrelle Pipistrellus pipistrellus and Soprano Pipistrelle Pipistrellus pygmaeus

Ireland’s two smallest bat species, and also the commonest, the Common and Soprano Pipistrelles are the bats most likely to be seen flying around soon after dusk in both urban and rural areas. Both have a rapid, twisting flight as they pursue tiny prey of midges, mosquitoes and small moths. A single Pipistrelle (weighing no more than 5-6g, a 1 euro piece) may consume as many as 3,500 of these insects in one night. Pipistrelles are frequently found roosting in houses, although they also roost in other locations such as tree holes. In houses they prefer to occupy confined spaces such as behind hanging tiles and soffit boards or between roofing felt and roof tiles, rather than the main attic space.

The two are called Common and Soprano because the latter echolocates at a higher frequency peaking at 55kHz, compared with the former which echolocates at a peak frequency of 45kHz. The Soprano Pipistrelle tends to form nursery roosts with larger numbers of individuals (up to 1,500) compared with the common pipistrelle which would typically have a much smaller nursery size.