My oldest pup doesn't mind a collar but we don't put it on her because of the jingling sounds when she walks. And our puppy HATES her collar and won't even move if she has it on. I should just leave it on her so she can deal with it!
our dog wears his collar from morning to night. i take it off him before he gets into his crate to sleep and then i put it on in the morning at the front door before we go outside. when he was a few months old, he HATED it. as soon as he saw it coming towards him, he'd start to chew on it so we'd spray it with Bitter Apple, and he got used to it. now he just stays perfectly still when i put it on him. his dog tags jingling is how we keep track of where he's going in the house since he's short
all my cats are indoor cats, the older two don't wear collars, but the youngest does only because it was what he knew before he came to my home, plus its got a bell on it, so you always know where he is, which is pretty nice
All my kitties wear collars, they didn't like it much when they were young but they got used to it. Just wear it on them, and ignore their protests. And ditto about the bell. Oh and get those with the safety catch types.