Common pipistrelle

The common pipistrelle ("Pipistrellus pipistrellus") is a small bat with a very large range across most of Europe, North Africa, southwestern Asia, and possibly into Korea. It is one of the most common bat species in the British Isles.
It is 3.5–4.5 cm long with a wingspan of 19–25 cm, with brown fur. It is common in woodland and farmland but is also found in towns, where it roosts in lofts and buildings.
In 1999 the common pipistrelle was split into two species on the basis of different-frequency echolocation calls. The common pipistrelle uses a call of 45 kHz, while the soprano pipistrelle echo-locates at 55 kHz. Since then other differences, in appearance, habitat and food, have also been found.
Echolocation.
The frequencies used by this bat species for echolocation lie between 45–76 kHz, have most energy at 47 kHz and have an average duration of 5.6 ms.