-snip-
That's wasteful.
Leeches are harmless and very important for medical practices.
We still use them today in a lot of practices, and they're useful in studying microsurgery.
It would also be a shame to get rid of flies/maggots, as they're really useful in helping with cases of gangrene and other necrotising diseases. They literally eat away all of your dead flesh, but they leave most of the healthy living flesh in place, so it can heal properly.
