What style feeders do you have, and are there Bee Guards to fit your feeders in the feeder accessories available.

Mine are all saucer style, feeding ports are quite small and don't allow a wasp or bee to feed. I occasionally see a wasp (like one) hanging around a feeder but it gives up and moves on, is not a daily occurrence. My feeders are all the same style, but different brands. I know there is at least one Perky Pet Saucer style, maybe a HummZinger or two and one that I know is an Audubon saucer style feeder. No regular visits from wasps at any of them and I have had a problem with yellow jackets ground nests here from time to time - it's not a wasp free zone ;0).