Bird Gravel Keet 24 Oz. This Bird Gravel Is A Vitally Important Digestive And Hygienic Aid For All Parakeets, Cockatiels, Love-Birds, And Parrots. Gravel Is Nature'S Substitute For A Bird'S Teeth. The Gravel Also Contains Oyster Shells, A Natural Form Of Grit, And Charcoal, Which Combats Hyperacidity And Sweetens The Stomach.