At Cracked.com I came across a fantasticly irreverent article about the five most horrifying insects in nature, including the bullet ant, the Japanese giant hornet, and of course, the botfly.
There are dozens of varieties of Bot Fly, they’re each highly adapted to target a specific animal, they have delightfully descriptive names like Horse Stomach Bot Fly, Sheep Nose Bot Fly and, hey, guess what. One of them is called Human Bot Fly.
And since botflies can become lodged into any part of the body, it is not unheard of for them to make their way into the human brain and, well, *feed.* Behold:

The human botfly is found only in Central and South America, and it lays its eggs on a mosquito (or other biting insect). When the mosquito bites a person, the eggs fall onto the skin and are hatched by the warmth of the body. The larvae burrow into the skin and then travel throughout the body–and can move across the blood-brain barrier, and cause meningitis and death after growing inside the brain, eating and destroying it.
Hat tip Aaron.