Kim,
Basil wears a collar, quite honestly for the benefit of us hoomans. He looks cute and actually likes wearing it. (He brought it to me last night! ) If you are worried about your kitties getting hurt, get them the "SAFE CAT" collars, they are made to open up if a cat is struggling. They sell them at PetSmart and other stores.

Noah and Noel wont tolerate a collar, so they dont wear one. All the cats are strictly indoors.

So, 12 cats! How great! Is it hard to remember all those names when you have to call them?