FWIW I do not see any sign of fresh muskrat activity. The damage looks like burrowing crawfish damage to me.
Look familiar?
https://www.google.com/search?q=burrowing+crawfish+damage&biw=1366&bih=599&tbm=isch&imgil=1OEQPL1A1RStiM%253A%253BjUoh4bAE5iD7jM%253Bhttps%25253A%25252F%25252Fwww.ces.ncsu.edu%25252Fdepts%25252Fent%25252Fnotes%25252FO%25252526T%25252Flawn%25252Fnote126%25252Fnote126.html&source=iu&pf=m&fir=1OEQPL1A1RStiM%253A%252CjUoh4bAE5iD7jM%252C_&usg=__OI1LSF7NQf1vuI4wXssMRiRc2Eo%3D&ved=0ahUKEwiL4dC67s7JAhUKPiYKHaOkCsgQyjcIMg&ei=xCloVovvJIr8mAGjyarADA#imgrc=1OEQPL1A1RStiM%3A&usg=__OI1LSF7NQf1vuI4wXssMRiRc2Eo%3D
Last edited by Bill D.; 12/09/15 08:30 AM.