Botflies are typically known as internal parasites because of their larvae. Female flies of this kind lay eggs within the skin of a mammal, humans included.
The resulting larvae can be extremely dangerous and result in an infestation known as myiasis, where skin tissue undergoes severe change.
Worse still, in humans, the transmission is often done via ticks and mosquitos. The sight of larvae wriggling under the skin is unsettling, to say the least, and many botfly larvae carry deadly parasites within them that can severely harm you.