1.There is a inside the grass ball. When your pet plays with it, it will make a sound to attract the pet's attention.Great for playing and nibbling, help prevent boredom. 2.Chewing Grass ball promotes clean and healthy teeth while satisfying your pet's natural instinct to chew 3.Suitable for cats, rabbits and small rodents pet play, but also for small pet rodent bite, ideal for small pet toys molar tooth cleaning. 4.Also this product can be as funny cat stick, cat climbing frame and other products. 5. Handmade ribbon ball, carefully woven and tied, it uses no adhesive making it extremely natural and an ideal toy for all pets. NOTE: Please let your pet not eat the . Product Description Color: Yellow Material: Straw Size: 10CM (3.7 inches) Package Contents: 2 x Ball Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.