Bat skull

Bats, a collective term for mammals in the order Chiroptera, are mammals with the ability to fly. The forelimbs of bats are extremely slender except for the first finger, and there is a thin and hairless wing membrane between the fingers and between the forelimbs and hind limbs. Usually, there is also a wing membrane between the hind limbs; Bats are divided into two categories: large bats and small bats. The name Chiroptera is derived from the characteristic that the forelimbs or hands of such animals degenerate into wings. Beneficial to humans due to its extensive predation of insects, it plays an important role in agricultural and forestry ecosystems, and the excrement in caves is made of high-quality phosphorus fertilizer. Some bats are also carriers or hosts of pathogens and can cause harm to fruit trees.