Nail Nibbling

My cat chews his nails. I wonder if it is a stress thing but from reading cat based websites like the www.messybeast.com, it is probably just a normal behavior. Gnawing to get rid of the nail cover so the nail is continuously sharp. My dog used to suck his paw. But I never figured out why he did that. But he certainly was cute. He was even cuter than the Thurber dog below.