I had a kitty that HATED collars, she would work at them until they were off. Eventually I gave up.

Most of my cats had collars, although I quit having my senior citizen kitties wear them the last couple of years (and both Herald and Bonnie have crossed the Rainbow Bridge). Had one cat that would loose his, and I'd come home to find the collar around my front door knob. A neighbor would find it and return it. That particular kitty would loose them in fights, or prowling around the neighbors shrubs. It was funny the places they'd find the collar.