Bergholmen

Date of Observation
Sighting Details
Do you know what species you observed?

Nope

What did you observe?
Can you give further details on the observation e.g. behavior, habitat etc:

They fly by our window every night catching mosqitos. Every 10-15 seconds there are a fly by. 

How many bats did you see?
26-50
How did you identify them
Visually Identified Bat