Other - Depends on the dog.

Shadow - 100% of the time, she looks funny without it and loves her collar. I'm not worried about her running off or anything.

The rest of the dogs, it depends. They always wear a collar - with tags - when going out somewhere but that's about it. Jack is chipped and he's the one that wears the collar the least.

One of the three cats has a collar, because her and her sister are so similar it's nice to be able to tell them apart at a distance. Haha.