Ya, don't underestimate a hungry raccoon in his own territory...I wouldn't be surprised if he was able to lift the edge up and slip underneath. I live in SD too and I've had lots of problems with raccoons and possums -- both love to eat my chickens. Last week I bought a motion-sensor sprinkler that sprays a short but tremendous burst of water...it seems to be working as a deterrent for our nighttime visitors. The kids are having great fun with it during the day too.