Do you know that external house doors and windows are two of the top 10 reasons that dogs get lost? In fact, according to the same study, a dog getting out via the "front door" is the second most common way a dog went missing. If they have the chance, many dogs and cats will take an open door or window as a chance to explore. Even if they love you and your treats and toys, they will still want to go explore. Below are 10 simple ways to "Houdini-proof" the inside of your home.