What part of the country are you in?

In the NW, the botflies go after rats.  Sometimes right around this
time of year, the rats get so sick you can walk over and crush them
under the heel of your shoe.

Then, when you roll over the carcass, you will see 2 or 3 greasy
looking grubs, about the size of a large caliber handgun round, crawl
out of abcesses in the rat's abdomen.

There is an interesting book called "The Firecracker Boys" about
gung-ho scientists who wanted to use nukes to excavate a harbor in
Alaska.  Biologists studied the diet of the eskimos to see how they
would be affected by the radiation.  Among other things, they learned
that eskimo hunters quickly rip the hide off a fresh-killed caribou so
they can gobble up the botfly larvae raw, like peanuts.

Charlie