Booger does because he's an escape artist and can get out of this house and the yard with absolutely no problem, especially if he sees a cat, he HAD a chip, but it came out. I'm waiting until I have more money to go and take care of that. Doom, no, he doesn't, but his chip also stayed in. He mostly doesn't because it got wrapped around my toe once while I was sleeping and when I flipped (rather violently, apparently) it dislocated my toe. I hadn't thought of it being bad until then, but now I take Doom's collar off before bed. Has anyone yet discovered that I'm a bit accident prone?