Do you know what species you observed?
Additional question - Can you give further details on the observation e.g. behavior, habitat etc:
3 bats flying in a route between tree tops close to a house and catching insects. Most nights it's only 1 or 2. Seen and heard at 30 kHz.
How many bats did you see?
How did you identify them
Using a Bat Detector
Do you have sound files of recorded Bats