Have a cat that constantly wants to be let in and out of different rooms and various doors? Cat flaps - the mini-doors that let pets come and go as they please without your assistance - can be a blessing. They're not necessarily a license for complete feline freedom, however. Experts recommend that cat flaps be used in conjunction with electric fences to contain your pet within a safe area. Cat flaps can be made-to-order or bought ready-made in a variety of standard sizes and installed at home. But there is a downside: Outdoor cats that hunt can use the cat flap to bring their trophy prey inside. If you install a cat flap for your cat's comings-and-goings, make sure you keep an eye out for whatever the cat drags in!