A bee can get through 3/16" A bee can get through 1/6". A bee cannot get through 1/8".
The bees will plug the hole and to unplug it I use a hive stapel or w/e So Just heat up a staple and use that to make the holes The staple is a tight fit and the shb can get in but not the bees. My friend is the one that came up with this trap. plastic sandwich container with a lid glued in the center with the bait and oil on the out side of that