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A cat flap is a great option to give your pet some freedom and ease the burden of getting them out and in. It will also make your pet less stressed and prevent them from entering the home when they are not welcomed. To put up a cat flap, measure the distance from the bottom of the cat's stomach down to the floor. Draw a line across the door's frame. Utilize a spirit-level to ensure whether the line is straight. 1. The kind of door If you're installing an animal flap onto an uPVC door panel or a double glazing glass sea