Yes all of mine have collars, but they do not wear them when I am not at home. When I am home I put them on cuz I want to know where they are and if they are under my feet. I think common sense here is what is used. Like I said when I am at work all day the are in stealth mode and they love it, but they also like having them on. I take them off at night. When I take them for walks they wear a harness so they won't get away.I hope this did not afend anyone out there.. Candy & The 6 Pillow Piranhas [Posted in FML issue 3002]