Muskrats, huh? I was guessing fresh water otters. Usually they are about 18" long from head to tip of tail, with their head about the size of a lemon. Generally, they take off if you get near them, however, when Mick and I were there last time one surfaced right between us and headed straight for Mick. It didn't care that we were there and this one was huge. I'd say it was about the size of my dog (border collie/black lab mix, 56 #s). Pretty freaky.

Still sound like Muskrats?

Oh yeah, they have medium brown fur.