A cat flap is basically a hole that you can insert into your door to allow your cat to come and leave whenever they want. This design isn't particularly secure and allows burglars access to your home. You may also want to look into upgrading to an automated or lockable https://cat-flap-fitters-near-me61285.blognody.com/31124013/using-a-cat-flap-in-bifold-doors