In the uk some hospitals use maggots to clean wounds such as ulcers that resist anti-biotics - they only eat corrupted flesh.
The French aristocrats, way back when, used to take a young pig with them when they travelled. At their night halts their servants would place the pig in the bed for an hour or so then remove it before the aristo went to bed. The fleas and bugs, well dined, slept the night away as well.
Funny thing is, we have three types of fleas that infest us and the only other animal that they inhabit isn't any of the primates or monkeys, it is the pig, so we are close relations after all!