When insect taxonomist Chris Carlton of Louisiana State University went on a collecting trip in Belize, he did what many travelers do: He picked up a souvenir. It was even free, which was pretty sweet. After spending a month in Central America, he returned home and unwrapped his gift to himself.

Unfortunately, the unwrapping happened on the top of his noggin. Carlton’s scalp had become home to a human botfly larva, a spiny parasitic maggot that digs into living human flesh, feeds on the inflamed tissue surrounding it, and grows to more than an inch long.