Human Bot Fly
Hello! Meet the human Bot fly. Looking a bit like a bee, but without a mouth. Because they don't eat in this stage. Creepy. Bot flies tend to visit cinemas and sit next to those who most look like they want to be left alone. Even though they can't eat, they rustle crisp bags through the entire film and kick the back of your seat sporadically, and sometimes put their bare feet up on the headrest of the seat next to you.
If that doesn't work, they'll put their little clammy feet on your legs. Their favourite hobby is snatching mosquitos and putting their eggs all over them before letting them go. Then the mozzie lands on you or I, and when they make a little hole to feed on your delicious sugary blood, they inadvertently drop an egg or two it.
There, a fat little larva develops, in your groin, or wrist, or inner corner of your eye. The larva have backward facing tiny hooks the better to stop you getting them out. If you haven't already gone screaming to the doctor's demanding they take out the wriggly lump, after about a month, they chew their way out and get on with growing into a mouthless horror fly. Always check a mystery wound for a pair of spiricles folks.