This low reproductive rate is offset by the fact that bats live longer then most mammals of their size. Ernest P. Walker had a pet Eptesicus that attained an age of at least 13 years. The Zoological Society of London had a fruit bat for 17 years, and there are records of bats marked in the wild that lived at least 30 years. The sperm is retained in the reproductive tract of the female during the winter. In the nonhibernating forms, ovulation and breeding occur in the spring or at favorable seasons.
Bats destroy many harmful insects and pollinate many flowers.
People eat some of the larger bats. Some animals that feed on bats are the birds of prey, snakes, and other mammals, including other bats. The congregation of bats in caves facilitates the preservation of their bodies after death. Ernest P. Walker encountered such a condition in a lead mine in Mexico. The mine was merely a fissure two to eight feet wide that had been worked out.