I tried the 4x4 ones but found the most effective to be these ones made from a 2x4. Drill the 3/4" main hole in the edge of the board and then drill a 1/2" hole at a 45 degree angle until it connects to the 3/4" one. Then attach the lid of the jar to the edge of the 2x4 with two screws and drill the same 3/4" hole into the lid. Screw the jar on. I also used two Walmart water bottles by drilling a 1" hole into the 2x4 edge and then epoxy the water bottle lid into the hole. Once dried cut the hole in the lid to match the hole in the wood. Screw the water bottles on. The water bottle one seems to work best and you can take an 8' 2x4 and place multiple bottles on it. Then screw the 2x4 where the bees are active. The last thing I did was fill the holes the bees already had with caulk so their only option was the ones I offered or dig a new hole. I figured the bees are like people and will take the path of least resistance. I have about 12 caught in a few days.
