Beetle larvae, I can see that. But flies? They’re disgusting insects. Sorry if I don’t know what a fish cousin is.
A cousin that drinks too much.
Soldier flies look like black wasps. They aren’t annoying like houseflies are and their maggots don’t look like housefly maggots they are different...dry to the touch, not slimy...looking at them doesn’t make me queasy like common fly maggots tend to do. Soldier fly larvae actually eat housefly eggs and debris so if you have soldier flies you won’t see regular flies much if at all. They’re actually pretty neat and can very quickly convert a stinking mass of wet bird poop and rotting seed hulls to an odorless dust. I wouldn’t want to kill them to eat myself cause they prevent nasty barn bugs and pests, but chickens certainly love to eat them and larva make good fish bait or feed.