A Fun Way to Challenge and Entertain Dogs for Hours Simply place a treat in Our Zanies Giggle Peek-A-Treat Ball and challenge dogs to get it out. Provides a great way to ease boredom, alleviate stress and keep dogs mentally stimulated and challenged. Unique design features a transparent window in the center of the toy to give dogs a tantalizing view of the treats. Two air vents inside emit hilarious giggle sounds whenever the ball is rolled or shaken to capture dog's interest. Adjustable opening allows insertion of different sized treats and can be increased or decreased in size with a simple twist to make it easier or harder for dogs to retrieve treats. The 6" toy is made of durable, non-toxic plastic with a colorful bone design.