Eptesicus murinus (Linnaeus, 1758) The parti-coloured bat or rearmouse (Vespertilio murinus) is a species of vesper bat that lives in temperate Eurasia, from Western and Southern Europe, eastwards over the Caucasus and Iran into Mongolia, north-east China, Korea, Afghanistan and northern Pakistan.

The parti-coloured bat has a body size of 4.8–6.4 centimetres (1.9–2.5 in) with a wingspan of 26–33 cm (10–13 in), and a weight of 11–24 grams (0.39–0.85 oz).

These bats hunt for their prey, for example mosquitoes, caddis flies and moths, with a wide range of ultrasonic sounds, but especially around 25–27 kHz.

[6] They hunt after twilight at heights of around 20–40 metres (66–131 ft), for example in open landscape over streams and lakes and above forests or at street lights.

In Western Europe, male groups consist of about 250 animals and are found only during the spring and early summer.