Sugar water or soda in the bottom of a 2 liter. Just need a little. Then put a little funnel at top and boom, you got yourself a trap. You can also cut the top of the two liter off and flip it upside down to create the trap and duct tape it. Yellow jackets can't resist sugary drinks and will go in and drown.
Ok, not to sound too clueless here, but I'm not picturing the mechanism you're talking about when you say "You can also cut the top of the two liter off & flip it upside down to create the trap & duct tape it." I'm taping what to which & turning it how? Filling it with sugar water/soda? Because if you mean that I should cut the top off, flip it upside down & tape a funnel to the soda bottle...do you mean that I should turn it right side up again, fill it with liquid & then the trap is ready? So it's the same principle, just #2 has the funnel taped further down into the bottle, instead of at the neck?
And I'm guessing that I should put enough liquid in the bottom of the bottle to drown them? And that's what keeps them from flying out the way they came in? Because I've watched those little suckers go back into their nests & they are VERY precise. (One of the nests has them landing in TANDEM & they are spot on!) If they aren't dead, I can't imagine that a little funnel is going to stop them from getting out of the trap...