I would try taking the bell off - have only had to do it with one of my cats, the rest have all accepted it - and apart from her, all the cats I have put collars on have been 10+, I haven't known if they have ever worn one before, or how long ago if they had, and all have been fine - Molly currently isn't wearing hers, as I haven't figured out how to tighten the bit her name tag fits onto so it doesn't fall off. Lucy is the first cat in a long while to go out without a collar, i didn't get chance to try and find one that would fit her first!!