A cat flap enables your cat to come and go through his own door. Modern cat flaps of varying designs have features that allow you to adjust the access available, for example locking it at night or allowing ‘in’ only usage after a certain time of day. They are manufactured in varying sizes, some even accommodating dogs, and can now be fitted to non-standard doors, such as double-glazed units.
In theory it sounds like a great idea; you are out and your cat is free to choose where he goes. Cats need to maintain a sense of control over their activity and this provides it. However cat flaps can be a mixed blessing. When you are acting as doorman your cat knows that he has to ‘ask’ you for entry and exit. This gives him a sense of increased home security and the shut door represents a raised drawbridge, impervious to invasion. When a cat flap is fitted it potentially allows invading cats to take advantage of the breach in defences and steal food. Any owner will recognise the way cats stare at a cat flap for ages before they leave or those that jump when the wind catches it. It sometimes isn’t the perk we would like it to be.
To minimise the risk of other cats entering your home it is possible to purchase flaps that offer the resident cat a degree of exclusivity of entry. A magnetic key that unlocks the flap can be attached to a cat’s collar but this relies on the cat not losing the collar and no other cat in the neighbourhood having a duplicate key! The process of disconnecting the locking mechanism also takes a few seconds so hitting the flap at a run, with an adversary in hot pursuit, is like hitting a brick wall. Once your cat unlocks the flap and gets indoors there is no guarantee that the other cat won’t get in right behind him.
Modern exclusive entry cat flaps now work by reading the individual’s microchip under the skin on the back of his neck that is there for identification purposes. While this system isn’t perfect either it goes some way to resolving a few of the problems.