One of the best ways to identify bat species, is by using a bat detector. Bats use high frequency calls generally higher than the range of human hearing. They use their high frequency calls to build up a sound picture of their surroundings. This echolocation system enables them to wing their way through the night hunting insects in the pitch black. A bat detector makes these echolocation calls audible to humans by reducing the frequency so we can hear the calls thorough a speaker on the device. Luckily most of our bat species in the UK call at different frequencies, so with practice you can learn to tell the sounds apart, much like recognising a friend’s voice on the telephone.
Bat detectors can often seem complicated at first glance; so below there is a short video explaining why we need them in order to detect bat presence. The video also shows how one particular type of bat detector (heterodyne) works and gives a quick introduction on how to use them.