Two or three times a year the crows just get a little to fearless and become a problem. I have a fake stuffed owl and a crow decoy. Put the decoy above the owl in some low branches, ghillie suit and a few quick calls and in they come. It's fast and furious!!!! after the smoke clears the crows will be around but very cautious. Most of the time it's a reasonable mix of crow and hawks and all is well.