My cat regularly pulls out her blunt nails when she grooms herself, and I know that’s normal. Recently I had my pinky toe injured, and now it’s bruised, won’t bend, and has a subungual hematoma. I was just putting my feet up to rest when she came over and started grooming my feet. (She likes feet.) Then, she fixed her teeth on my injured toe and pulled hard. She only got through the bandaging, but is this related to her regular grooming behavior?
Animals (and humans btw) can distinguish materials and textures they lick. If your cat has a habit of grooming you, she knows how your skin or toe is supposed to feel. If there's something obscuring your toe, she may try to remove the foreign object just like she would remove dirt from her fur. She may also lick your injured toe more than usual because she feels the injury (change of texture and temperature of your skin).