I should microchip all of my pets! I have a boxer and a terrier and two cats and none of them are microchipped. But to do them all at one time might be too costly. I am not letting Marley outside right now because she is new and too little. But once she gets bigger she will be an inside/outside cat like Koko. Koko does not wear a collar and he has never gotten lost. He is such a good cat, too. He doesn't even need to use the litter because he does his business outside. He always stays around the yard, but I'm afraid Marley will wander, that's why I wanted to get her a collar.