Who says doggie doors are exclusive to canines? One Florida homeowner learned firsthand that the easy access has a downside. Alexis Dunbar came home to discover a six-foot alligator slithering along the floor of her bedroom. Apparently, he snuck in through the doggie door. Interestingly, she does not have a dog; the door was for Dunbar's cats, who were both alive and well.
I also use a small doggie door for my cats. It's located inside the house so they can go in the laundry room and use their litter box without a dog rudely interrupting to grab a "snack." (Ick!)
My aunt also uses a doggie door for her inside-outside cats. One night, she woke up in bed because her cat was being so restless, moving all around the comforter. She repeatedly shoved him away until she realized that both of her cats were scared stiff in separate corners of the room, hissing their little hearts out at the intruder: a raccoon! My aunt screamed and managed to shoo him out of the house. For weeks, she had noticed that the cats' food bowls emptied more quickly. It had never occurred to her that a thief was sneaking in for a bite to eat. Do you have a doggie door? Ever have a surprise houseguest?