One doctor thought the bleeding, strange bumps on Aaron Dallas' head might have been a gnat bite.
A specialist thought it was shingles. Then the bumps started to move.
It turns out five bot fly larvae were living on Dallas' head, near the top of his skull.
The Carbondale, Colo. man says he could feel them moving when he put his hand on his head, and he could hear them too.
Dallas says he likely received the larval infestation while on a trip to Belize this summer.
Doctor Kimball Spence says he removed the bugs Thursday.
Spence says bot fly infections are fairly routine in parts of Central and South America.