We've had some here this summer. I've used a short juice glass with a piece of banana in it, cover the top with plastic wrap, and poke a couple holes with a pencil in the plastic wrap. They get in the glass but not out. Once a day I'd cover the top with my hand, take it outside, and open the plastic wrap. Seemed to work pretty well.
Did you try tagging their ears to see if the same ones return?
__________________
Pretending to play golf since 1989