A dipterous insect of the family (Estridæ, of many different species, some of which are particularly troublesome to domestic animals, as the horse, ox, and sheep, on which they deposit their eggs. A common species is one of the botflies of the horse (Gastrophilus equi), the larvæ of which (bots) are taken into the stomach of the animal, where they live several months and pass through their larval states. In tropical America one species sometimes lives under the human skin, and another in the stomach. See Gadfly.

stout-bodied hairy dipterous fly whose larvae are parasites on humans and other mammals

Oestridae (also called botfly or bot fly) is a family of Oestroidea. It is one of several families of hairy flies whose larvae live as parasites within the bodies of mammals, such as the Desert Woodrat. There are approximately 150 known species worldwide.