My cat is grooming so much that bald patches appeared — what is overgrooming?

Quick answer

Licking a specific spot (usually the belly or inner legs) until the skin shows red through missing fur is called overgrooming. Causes include 'physical' factors like itching from dermatitis or allergies, or 'emotional' factors like stress and anxiety from a move, unfamiliar people, or litter box dissatisfaction. Temporarily use an e-collar to stop the licking while you identify and address the underlying cause.