Every day, he goes under my couch to grind his shell on the dull metal parts underneath it. Today, he discovered that he can grind against my fingernails.
He seems to be primarily interested in grinding out the groove between the main plates on his back and that outer ring that goes all the way around.
When he grinds himself on the couch or on my fingernails white, flaky stuff comes out from between the scutes like when you file your nails. doesn't appear to hurt him-- It actually makes his shell look better, but I wonder if something isn't the matter with his health that is making him do this. He won't allow me to clean him with a toothbrush in water or anything because it upsets him, but if I offer to "clean" him with my fingernail, he will absolutely go nuts and just grind against my thumbnail for 10 minutes straight. I think it feels good to him, but I just want to make sure he's not hurting himself.
I have all the proper equipment and diet. He has not shed in over four months. He will not eat tomatos, blueberries, or apple peel, but likes everything else on the recommended feeding list. He gets cuttlebone just about every other day, veggies every other day (lettuce, carrots, sweet potato), pellets every other day, and shrimp as a treat.
Shell photos:



