https://opensourcebridge.scien....ce/wiki/How_to_Train
You're tired of having get up to open the door to your pet. A cat flap could be the answer. Pet-flap fitters can install them on any type of door that is available, including uPVC or composite doors. They can also be installed in certain types of walls. Security It is not uncommon to see cat flaps incorporated into doors, but there are also a lot of people who have them installed into windows or double glazed doors. If you don't have a wooden door or wall, having one installed into glass is a great ide