All good suggestions, but maybe I wasn't clear about the situation. This happens when I'm not in town, so guns, and dogs and cats that need to be fed, won't work.

And you guys are into serious overkill... these are squirrels--.22 LR works fine. And the neighbors are too busy shooting their own squirrels to complain.

I left D-Con instead of antifreeze but I think what happens there is that they are into nesting mode and don't stop to eat. Or they chew the liner and eat the poison and die and a thousand other squirrels climb over their bodies. Hood liner is good stuff, to a squirrel.