I live on a farm and there are always mice problems no matter what I
do. But once there was a rat problem in the barn, which I stopped by
putting all my livestock feed into metal containers, and getting about
a dozen outdoor cats. However, one of the rats got into the house,
and I traced it to a hole next to a drain pipe. That day I went and
got a can of Great Stuff and plugged the hole. The next day I heard
the rat digging away the Great Stuff around that pipe. It was really
gnawing away at it. I took a nail and punctured a small hole in the
Great Stuff, and could tell there was little left. Everything got
quiet for a few hours. That night I heard the scratching next to that
pipe again. I carefully inserted the plastic tube on the nozzle of
the Great Stuff can into my nail hole, and let him have it full force
from the can. I dont know if it was just luck, or if I embeded the
entire rat in that stuff, but I never heard from that rat again. I
still wonder if the rat is permanently encased in foam.

So, Great Stuff will NOT stop them, unless you are lucky enough to get
it on them directly. I doubt I'd ever be that lucky again.


Great stuff alone won't stop rodents. If you really want to stop them, fill
the hole with steel wool, then fill the hole with Great Stuff. The
can't/won't chew through the metal.