Doggie Door Bell

I have begun fostering dogs again and my current foster refuses to bark to let me know when he has to go out. But, he is housebroken, we just have to watch him and keep an eye on the time to know when he has to go. I know a bunch of friends that have been successful with bell training so I figured I would give it a shot. I'm so glad I did. I found this one on Amazon: https://www.amazon.com/dp/B01M1SD9WK/ref=cfb_at_prodpg and decided to give it a try. So far, I love it. It hangs on the door perfectly and doesn't make noise just because the door is opened/moved. We have to actually nudge it to make sure it makes a sound. Right now we are still working on helping him associate the bell with going outside. That is working great, as he knows that when the bells ring it is time to put his leash on. Now we are starting to work on having him ring it. He's not catching on to that quite as quickly but I know he will.