There are eight different species of bats known to live in Northern Ireland. In the Belfast Hills the most common bats are pipistrelles and Leisler’s which roost in both trees and buildings. The saying ‘blind as a bat’ is totally unfounded as bats have very good eyesight. Their most highly developed sense however is hearing as they use a form of sonar to locate their food. One pipistrelle can eat up to 3,500 insects in one night.