A botfly infestation occurs when a mosquito or other insect carrying botfly eggs deposits them onto a human, at which point body heat causes the eggs to hatch. The resulting larvae burrow under the skin, feeding on the surrounding tissue, where they can remain for up to eight weeks.
A botfly infestation often requires surgical removal, as the maggots are difficult to remove and cause pain. The affected area swells as the maggots continue to grow, and the host may be able to feel them moving around. Botfly maggots have been pulled from all areas of the body – anywhere that could be bitten by an insect.