BLUE Naturally Fresh Cat Litter comes from Blue Buffalo, the makers of natural food and treats for dogs & cats. Blue Naturally Fresh cat litter is unique because it's made with walnut shells. Walnut shells are a 100% annually renewable non-food agricultural product and are also 100% biodegradable. Walnut shells have a greater absorption capacity that leading cat litter brands, and they provide superior odor control. Even better, it's 100% natural, environmentally friendly, and made in the United States. Blue Naturally Fresh is available in several varieties - Quick Clumping, Multi Cat, Pellet, Scented Multi Cat, and Herbal Attraction. Herbal Attraction litter is formulated with naturally scented herbs that have been shown to be effective in attracting cats back to the litter box.