Bats feed on nocturnal insects such as moths that are apprehended during flight. For orientation and location of the prey, bats use an ultrasonic radar system: Bats produce ultrasound that is reflected if it interacts with any object. From the time it takes the reflected sound wave to return to both of the bats’ ears, the animal can determine the position of an obstacle as well as of tiny prey items in its surroundings. Humans cannot hear ultrasound however we can use a bat detector to convert ultrasound into audible frequencies. Some bat species can be even identified with the help of the frequency and sound pattern of their radar system.
There are two colonies of the Common Pipistrelle Bat residing behind the wooden blind of House Sorgschrofen. Just before dawn they animals start to “look” for insects, or should we better say “hear” for insects? We observe the bats hunting near artificial light and in the vicinity of the creek and the woods. When it is dark we can’t see the animals any more, but we can hear their ultrasounds by using our bat detector. By the way, the device is also suitable to hear grasshoppers.
