Cool story, I think about that a lot. We're on 5 acres and a neighbor's dog killed our female Guinea fowl. We've had 3 bear attacks, so now the coop's electrified. We can't seem to find a female Guinea and we don't want 15 of them, lol.
DE keeps lice, and also keeps worms away, so to me is very important. I always use the food grade one. Pertaining to the previous comment, I didn't know it kept flies away too.