As mammals, bats sport fur instead of feathers, give birth to live young and feed them milk. They also rely on regulated body temperatures and well-developed nervous systems. Unlike other mammals, bats can fly, and they use high-frequency sounds to detect obstacles when flying at night. One of the smallest bats, and the world's smallest mammal, is the bumblebee bat of Thailand. The tiny bat weighs less than an ounce. The common little brown bat has the world's longest lifespan for a mammal of its size, sometimes living more than 32 years.
Bats live in all parts of the world except for extreme desert and polar regions. Most species live in tropical forests, with 75 species living in southern Africa. Not all bats live in caves: The little woolly bats of West Africa live in the webs of colonial spiders, while banana bats roost in the curled-up leaves of banana plants. Some bats roost in animal burrows, termite nests and rock crevices. In colder regions, bats hibernate or migrate to warmer areas, where they find an abandoned mine or cave to survive the winter.
Bats eat a wide variety of foods, depending on the species. Some bats eat flowers; others rely on flower nectar as an important food source while helping to pollinate the plant. Some eat fish, and many feast on insects such as mosquitoes, beetles, moths and gnats. The gray bat eats more than one-third of its 3-oz. body weight in insects each night, equivalent to 3,000 or more bugs. Other bats, such as the pallid bat of North America, eat scorpions and large centipedes, relying on its immunity to stings to help it survive.
Bats primarily eat insects, making them welcome residents in areas with plenty of mosquitoes. Bats also eat rootworms: A colony of 150 bats can eat up to 33 million rootworms, helping to protect crops that would otherwise be damaged. Some nectar-feeding bats help pollinate plants in the desert, especially cactus.
Bats in the northeastern United States are being killed by the thousands by white-nose syndrome, a fungus that grows on the bats' muzzle, wings and ears. The disease makes bats use their fat reserves during hibernation, causing them to starve to death. The disease appears to be spreading across the southern United States, with large colonies of bats the most threatened since they pass along the disease. Bats also face threats from disturbances by people who invade their space or try to collect them. Pesticides also contribute to the demise of bats.
