Chuck and I have talked extensively about what happens to a body after it loses that 21 grams, mainly because I’m twisted and Chuck coddles me. In the rigor mortis podcast, we mentioned the bottlefly, which forensic investigators use to make ballpark estimates of time of death and the like. These investigators take samples of the maggots and larvae, measure them and so on to figure out how long they’ve been ingesting the dead flesh of a corpse.

Cool enough, but what if a fly laid eggs and they hatched and began feasting on flesh of a person who was still walking around and could be really upset by this? My friends, it can happen! Lemme tell you about the botfly.

This big, furry fly, native to South and Central America, employs phoresy, relying on other species to spread its seed. Females deposit their fertilized eggs onto mosquitoes, which bite humans and lay newly hatched botfly larvae beneath the skin of the victim. Here’s where it gets awesome.

The fly eggs hatch and the larva is hungry, so it feeds on the subcutaneous tissue of its mammal host, a process called myiasis. The tissue of us mammals don’t react well; the burrowed, feeding and growing cause a rise in white blood cell counts — what with the maggot being a foreign invader and all — and the area surrounding the infestation becomes inflamed and secretes pus. Even worse, to breathe, the larvae remain relatively close the skin’s surface and human hosts have reported feeling them squirm when touched or if the pustule is covered. Yes!

After about 30 to 90 days, the larva burrows out to begin the pupa stage. For those who don’t like to wait until a botfly larva eating the fat and tissue beneath the skin is full and ready to leave, there are medical procedures — essentially popping the larva out. If you like, watch the video of just such one procedure, embedded below.

And if you dug this post, then you’re going to love (love!) a new show from HowStuffWorks.com’s parent company, called “Monsters Inside Me.” It premieres tonight and will be on Wednesdays at 9:00 p.m. Eastern on Animal Planet. Check it out.

Here’s that medical procedure:

More on HowStuffWorks.com:
What causes rigor mortis?
Parasitic Infections Overview
What do bugs have to do with forensic science?