It should be noted that electronic pet doors are designed for controlling traffic and not designed for home security. When securing your home against burglars, an electronic pet door should be viewed in the context of the overall security plan for your home.Most automatic pet doors are unidirectional; they are designed to keep other animals out by barring access, but there are some that are bi-directional asin the example that follows. The technique to identify your pet varies by manufacturer and by product, the most common being through the use of infrared or electromagnets. By way of an example, one manufacturer uses a small magnet that is attached to your cat's or your dog's collar. The magnet acts as an identification tag, similar to way a magnetic keycards work in office buildings. When the animal comes in close proxmity to the pet door, a circuit is activated, which triggers the release of the flap. This provides entry for selected pets i.e. only those that have the correct magnetic key on their collar. Other animals are barred access. Features of these doors include: Selective access through the use of a magnetic tag on the pet's collar. Stray cats, dogs, raccoons, possums, skunks and other pests are restricted from access through the use of a 4-way lock 1: Keep strays out while allowing your pets free access either way. 2: OUT ONLY - Your pet can go out but cannot come back in. 3: IN ONLY - Keeps your pet in at night 4: No access either way for any animals These doors are typically battery operated so there is no need to mount near an electical socket.