Walmart sells a nylon strap with 3 bells attached to it. I bought a couple and they work great. Loud enough for me to hear, but they didn't scare the dogs like other bells. The trickiest part is, when the puppy does start ringing the bell on his own, he will start out by just barely tapping it. You have to watch closely for it, and reward him immediately by taking him out. This is how I ended up running outside barefoot in the snow a few times! |