To my untrained eyes, moles, beavers, and groundhogs look quite similar.

(A mole / http://en.wikipedia.org/wiki/File:Close-up_of_mole.jpg)

Image references:

http://www.google.com/search?q=mole&hl=en&qscrl=1&prmd=ivns&source=lnms&tbm=isch&ei=vbvYTZ2NOILL0AGXx838Aw&sa=X&oi=mode_link&ct=mode&cd=2&ved=0CB4Q_AUoAQ&biw=1280&bih=675

http://www.google.com/search?q=beaver&hl=en&qscrl=1&prmd=ivns&source=lnms&tbm=isch&ei=y7vYTbvoHYXd0QHwmpT8Aw&sa=X&oi=mode_link&ct=mode&cd=2&ved=0CBYQ_AUoAQ&biw=1280&bih=675

http://www.google.com/search?q=groundhog&hl=en&rlz=1G1GGLQ_ENUS250&qscrl=1&prmd=ivns&source=lnms&tbm=isch&ei=5r3YTbibIee70QHd25j8Aw&sa=X&oi=mode_link&ct=mode&cd=2&ved=0CBUQ_AUoAQ&biw=1280&bih=675