Bot-fly is a descriptive term used to describe a fly in the Oestridae family that lays its eggs in live mammals, including humans, causing uncomfortable and painful disturbances. Alternate terms used for bot-fly include warble-fly, heel-fly, and gad-fly. These names depend on the location and the animal affected. In Africa, for example, the tsetse fly is the carrier of Trypanosoma, the causative organism of the African Sleeping Sickness. When breeding in cattle, they are referred to as heel-fly. Similarly, in the United States, the bot-fly is commonly known as the horsefly, which as the name connotes, is usually found infesting horses and other domesticated animals. Regardless of the term used, the bot-fly remains a pesky and unwelcome parasite.