Jillian, my cat, broke the screen out of the window and was lost for a week. We called and called for her every day at feeding time but Jillian either could not hear us or could not find her way home. Finally, our local vet called and said someone had found Jillian and her microchip indicated that we were her owners. My neighbor across the way had found Jillian and was thoughtful enough to take her to the vet where she could be scanned and realized she had an owner. My baby is home! Without the microchip, Jillian would have been lost to me forever.