Bats were once very common, but now populations are in great decline. Partly this is due to an irrational fear of bats. Common misconceptions are that bats will pursue and bite animals, become entangled in one's hair, and that they all carry rabies. In California there is a greater incidence of rabies in skunks and foxes than in bats. Most people will bring a dead or dying bat to the public health department, but will not bring a dead or dying skunk or fox to diagnose its condition.
People continue to fear bats, and when they are found in their homes the bats are often killed.
Another cause is the use of insecticides in agriculture, which are killing bats in great numbers. The insects for which the insecticides are applied are becoming resistant to the deadly chemicals. Instead being killed by the poison, the insects survive and carry the chemicals in or on their bodies. When bats consume the chemical-laden insects, the bats become poisoned and die. Pressure should be placed on the agricultural industry to use natural insecticides or even to attract bats to control insects.