This video is called Nathusius’ pipistrelle bats advertising for mates.
From the BBC:
1 July 2014 Last updated at 08:54 GMT
Bat recorded for the first time on St Kilda
A bat has been recorded for the first time on the remote Scottish archipelago of St Kilda.
The Nathusius’ pipistrelle, which is a rare sight on the UK mainland, was spotted by visitors last month.
The bat was found on St Kilda’s main island of Hirta, resting on the wall of a small, stone-built store known as a cleit.
Nathusius’ pipistrelles are a migratory species and were first recorded in Britain in Shetland in 1940.
The islands once had house mice, but they died out after the last human residents abandoned St Kilda in 1930.
The National Trust for Scotland, which manages St Kilda, said it was not known from where the bat had flown.