I've had company (family) visiting and my large dog has been getting worse and worse about their movement in and out of the house. He actually nipped my son's ankle as he walked past him (dog was lying down). The shock collar was put on the dog. He's a bull-headed dog that knows his commands but often choses to ignore them. I put it on the lowest setting and had to use it, just one tap, after giving him the command "come" twice. That's all it took. Now he's listening.That collar is off and his regular collar is back on as he doesn't know the difference. He will be a mannerly dog for weeks then he slowly begins to revert.