Locking doggie doors work in much the same way as a standard door. It uses a hole in the wall or door to allow access for the dog, with a flap to keep the weather out. What’s different is that a locking doggie door can be secured. They can recognise either your dog’s microchip or a Pet Mate I.D. disc that comes with the door. As your dog approaches the door, it will automatically open, allowing free access. Once the chip or tag is out of range, the door will lock shut. There is also a manual closure for extra flexibility.