Oestridae (commonly called bot flies or botflies) is a family of Oestroidea. It is one of several families of hairy flies whose larvae live as parasites within the bodies of mammals. There are approximately 150 known species worldwide.
Eggs are deposited in animal skin directly, the body heat of the animal induces hatching upon contact. Some forms of botfly also reside in the digestive tract when consumed by a licking action.
When ready to emerge, a thumbnail-sized lump will appear and the Fly will break through the skin and fly away leaving it’s host alive with a small wound.