Today I saw on pintrest a picture of a simple fly trap you could make with 2 by 2's and window screening. It involves a box with a cone in it. Link here.... Fly trap for those without pinterest.. just search diy fly trap. It's there. You could check tons of flies. And could you then feed them to your chickens? Every other day or something so they don't rot maybe? My birds are not outside full time yet, and I imagine they will control a lot of the flies we have right now, but out in the back acres? It might trap other insects too. But mostly flies if baited right I would think. Flies are a protein source right? And if I already trust the flies they will find and snatch up, I could trust these flies would be okay right?
That thing will pay for itself many times over. If a similar device were placed on a float over a pond, flies could enter in the same way but instead of a tray or bottom mesh, tired flies would land in the water. Weighted side mesh could go just beneath the surface and the contraption could be suspended on a pole like a lantern. Fish would soon learn to feed under it. With blood as bait, it might be possible to trap mosquitos and other blood suckers.