This toy is a real favorite. I have a 22 month old mini aussie who is quite the busy girl. She loves this snake. It is heavy and long enough to make it fun to lug around. I haven't even needed to put treats in it. She shakes it, squeaks it's head and chews it. You can barely even tell she has chewed on it a lot! This one is a real success! One important thing to remember is to move out of the way quickly if your dog shakes it. It hurts (but not the dog - just us people).