Hunting and Feeding

Abstract

Bats eat the equivalent of half of their body weight every night. For insect eaters this can mean more than a thousand small insects, which in terms of energy is roughly the same as a person eating 30–40 hamburgers. Suckling females need an especially high-energy intake and can eat even more. So as not to put on excess weight, bats are careful to only eat what gives them most energy. Fruit eaters spit out fibrous matter, stones, and pips, and insect eaters usually bite off the indigestible legs and wings of their larger prey. The abdomens of swarming insects like ants and termites are rich in fat, and in order to maximise their nutrient intake, bats sometimes feast only on that particular part and spit out the rest. Many bats eat on the wing, while others, particularly those that hunt larger animals, prefer to land before savouring their meal in peace and quiet. Bats chew their food carefully to ease digestion and, owing to the large size of their stomachs in relation to their intestines, can eat a great deal when the occasion arises. At the same time, bats can digest their food and expel the waste in less than an hour.