Don't spoil your dog with dog crate accessories. We know this will keep your pets on their dog crates a live and kicking.
But I just saw this interesting article that shows an interesting method on how to make your dogs smiling.
I've not tried this but I think you can check this article and see if you can apply it to your pets. What do you think? :)
Read more about this article here: 5 Methods to Make Your Dog Smile