I use a live trap that has a one way door and have caught several at a time. Tractor Supply and Rural King sell a couple versions and, after looking at them, I made my own out of hardware cloth. Works great, throw an ear of corn or bird seed in it and leave. Come back later and give the critters a soak, empty it and put it back out for more. Mine gets loaned around to friends and family to get rid of the little pests.
TSC squirrel trap