I’ve made several traps in the past with varying degrees of success. Here’s one specifically designed that allows the yellow jackets to enter but not the honey bees. I think it is a 5/32 size hole. Last year I tinkered with the mix formula. Instead of totally sweet which would attract the honey bees I stumbled onto a mix of apple sauce, vinegar, and a spoonful of sugar (just enough to get a fermentation going). The yellow jackets like the CO2 and I think and the vinegar is not attractive to the honey bees. I used a 2 liter bottle and filled it about half way full in a short time. If you get your bait mix down it will not attract the bees at all and you can then open up the entrances for the yellow jackets.