No, they can eat through the gaps in #8 hardware cloth.....I have modified feeder ring things and I just invert plastic butter tubs with holes in the lid over the #8. Also, my observation hive has a feeder hole where an inverted quart jar goes, and the hole has #8 hardware cloth on it to keep the bees in the hive....I have inverted jars over an inner cover of sorts with #8 hardware cloth. I wonder if the small gap (a couple millimeters?) between the screen and holes in the jar lid is making it tough for them. Perhaps I'll remove a couple screens and see how they do.