muskrats dont eat fish theyre vegitarins(sorry 4 spelling) it was probly an otter if it was up north. if a muskrat was to come up a hole in your shanty it would only be to get a breath, they are very affraid of humans, i see it very unlikely one would do that, but if it did sya hi and open ur door 4 it. ive been trapping, hunting, and fishing my entire life and this is the 1st time ive ever heard of this.