Fine oyster shell grit is a natural source of calcium which is necessary for birds to form good, strong eggs. Provides wildlife with a natural source of calcium, essential during the breeding season. Oystershell Grit can also be used throughout the year as a mineral supplement to aid digestion. This product is also suitable for controlling pH in wormeries and often used by organic gardeners, who sprinkle the grit around the base of plants as a barrier to slugs and snails. Can be fed from feeding houses, bird tables and on the ground.