Birds have behavioral and/or nutritional needs for ingestion of soluble grit. Specially ground for all cage and aviary birds, HARI Oyster Shells soluble grit is completely digestible and provides a natural source of calcium which is required by all caged birds year-round and is essential when breeding for stronger egg shell formation.Birds with digestive problems may benefit from the addition of small amounts of soluble grit to their diet. If you suspect your birds has a digestive problem, consult your Avian vet regarding your bird's need for a soluble grit.