I've slept in shelters a lot over my 35 years of backpacking and never had a problem with mice chewing my sleeping bag or pad. Re food bag, I recall one instance - Rainbow Stream Leanto in Maine - where the mice were all over the place, including the packs hanging from the tuna can ropes. I hung my food in the tree that night.
In 2011 on my Colorado Trail thruhike, I followed Lone Wolf's advice and slept with my food in the tent every night. No bear issues at all, but about 2/3 of the way through the hike, I awoke to a gnawed hole in the tent floor. But they never got to my food bag.
I also agree.