We have all 3 of ours with ID tags on the back of their harness and they are microchipped as well. We are sooooo thankful that we had them microchipped. We once lost Rosie and the people that found her were going to keep her...they took her tag off. To make a long story short she eventually got into the hands of someone who took her to the vet to have scanned and one week later I got my baby back!!! It's well worth getting them microchipped. It's a quick pinch and then it's over. Some people have them microchipped when they are already under for spaying/neutering. Then they won't feel a thing!