My Border Collie, Grace, just loves this "toy." Dogs like Grace need constant mental, physical, and emotional stimulation and this thing helps for a few minutes in the evening. She has learned to check index every one, looking for a treat. When she finds one, she not only gets a treat, but she gets our praise. She has learned to use both her nose and her paw to manipulate the rounds. It is well built and heavy enough that it stays in place when Grace is playing with it. Because she still chews everything, after a few games, we take it up off the floor. Wonderful toy and I'm highly recommending.