Cat flaps are hinged entrances in doors or walls, which prevent the need for owners to let their cats in and out. Cat flaps are typically made from plastic, with basic models being little more than weighted flaps, while more advanced cat flaps are fitted with electromagnets which admit only a cat with a matching transmitter on its collar. Other models can be adjusted by the owner. Depending on their design, some cat flaps prove to have disadvantages.
Bring Prey In
Cats are notorious predators, and will often hunt in the backyard or further afield, catching prey such as birds, mice and even fish. When a cat catches prey, it tends not to leave it where it found it, but instead brings it back home. A cat flap provides an easy route for a cat to bring dead or dying animals directly into a home. Homeowners will often find these grisly presents left around the house, and in some unfortunate cases, the cat will be able to hide the body for several days before it is found.
Cat Marks Territory
Cat flaps don't allow a only household pet to enter and leave the house, but also provide access to other local felines. Because of this, a family cat may feel unsafe and even threatened in its own home. This lack of security can trigger a need, especially in a tomcat, to mark the home as the cat's territory alone, warning off other nearby cats. Cats mark their territory with urine, and may urinate throughout the house.
The standard cat flap typically measures around 6 inches by 8 inches, as noted by the Daily Mail Online newspaper website. This standard is perfectly acceptable for the majority of cats, but while variations on this size of flap exist, the basic cat flap may be too small to accommodate larger cats. Some breeds, for example, are bigger than the average feline, while in the cases of other cats, the feline may just be too overweight to fit through. A cat that squeezes to fit through a flap that is too small for it risks suffering injury.
The local cats will likely view a cat flap as an open invitation to enter a home as they see fit. While this may not be a troubling issue in the case of some visiting felines, problems can begin if the invading cat is a bully towards the family's pets, or else marks his territory by urinating in the house. This is particularly likely if the invading cat is a tomcat. The invader might also eat the family cat's food.