Botflies do burrow under the skin of mammals, though this pic is not real, the nasty--and not so little--parasite is the real deal. The term for a fly larvae burrowing under the skin and feeding off the living tissue is myiasis. Typically there are only 4 flies which will parasitize humans in this manner...then again, that's just 4 we know of. Cochliomyia hominivorax: 15-17mm long at maturity which is reached in 4-8 days. This little guy is found in South and central america. Cordylobia anthropophaga: 11-15mm at maturity which is reached in 10-12 days and he's found in central africa typically. Cordylobia rodhaini: a 23mm cousin of Cordylobia anthropophaga with the same distribution and incubation rate. and my particular favorite, Dermatobia hominis: 15-18mm with an incubation of 5-12 WEEKS! The human parasitic botflies of S. America with which I'm a bit more familiar have an interesting means of attaching to their human hosts. The female botflie catches a female mosquito and lays her eggs on the mosquito. When the mosquito finds a human for a blood meal, the human body heat triggers the botfly egg to hatch and fall onto the skin where the larva uses two anal hooks to attach itself to the host and then burrows into the flesh. Depending on where the larvae is located--and this can be anywhere a mosquito can bite you--there can be accompaning symtoms other than the excruciating stabbing pain and itching these little guys cause. A botfly infection called a WARBLE is typically a bump like a large mosquito bite than can grow to the size of a goose-egg in some people. The bite typically is swollen and red with a little pinpric hole that "bubbles" blood. this is the larval air hole. The larvae need this hole to breath through. I've heard a range of tricks that work well in extracting these guys, smothering their air hole seems to work best. Once the hole is located, take a heafty gob of vasaline, bag-balm, tigerbalm or a slab of lunch-meat or bacon and put it over the air hole. The larvae will have to come out of his hole and go up into the vasaline layer or the meat to get at the air, that's when you grab him with the tweezers and pull it out in one long firm motion--you don't want to leave any piece left behind to cause an infection. As with all parasitic infections SEE A DOCTOR! but if you have been in South or Central America--lower parts of mexico included--and you got bit by a mosquito and the bite keeps getting bigger and has a little blood oozing hole, you very well might have a bot fly problem and the quicker they're dealt with the better, and this usually means taking things into your own hands. So while in botfly territory, keep tigerbalm or bagbalm handy and spread it on every mosquitobite you get. Camphor penetrates deep into the skin and the bugs hate it. Don't be stingy with the bug repellent, and be sure to get checked out by a doctor when you get back. Botflies are nasty, but there are even worse killers to be found in the rainforests.