Bats are nocturnal because they find bugs during the night, and they can evade predators more easily at night. Bats stay away from daylight to avoid competing for food with other predators, such as birds. Bats are also active at night because they cannot see very well during the day, and they rely on hearing and bouncing echoes to navigate during the night.
Bats are also nocturnal because they do not have to venture long distances to find food at night. Many insects are active at night as well, giving bats a steady supply of food. Bats also take flight when the sun is down because there are few predators that can catch bats, other than a snake or owl that may get lucky.
Bats reserve the daylight hours for grooming and rest, and being active at night shields them from harsh weather. Bats are nocturnal because the sun can hamper their muscular system. The heat from daylight hours has a negative effect on the membrane of their wings, which can cause them to dehydrate, and the sun can lead to heat prostration. The night also allows the bat to regulate its body temperature and maintain body moisture. Flying during the night allows bats to escape harsh weather elements, which is one reason why adult bats have low mortality rates.