The best home security system ever designed are dogs! Hey, don’t laugh, I’m completely serious. I have one small dog that does the barking, and a medium dog that does the barking and biting. If you feed them, love them, and take care of them, they will take care of you and make sure you’re always safe. Plus, they’re portable. So not only are they home security systems, they can be car systems, vacation home systems, or going for a walk security systems.