These fruit bats go out at night in search of their favorite food, often returning to the same trees over and over again at distance of 12 to 25 kilometer from their caves . Experiments showed that bats seem to have a mental map of a large area of up to 100 kilometers,which includes familiar visual clues such as light and hills to help them go in the right direction. The bats probably also use magnetic fields and smell when they need to,but it appears that for their regular nighttime excursion they depend most heavily on their memorizes maps.