Scratch and Peck Feeds - Cluckin' Good Grower Grit Supplement for Chickens and Ducks - 7-lbs Grower Grit - 7lbs APPROPRIATE FOR LAYING POULTRY AGES 8-20 WEEKS NECESSARY FOR DIGESTION - Chickens do not have teeth. Grit is necessary for the healthy development of a chicken's gizzard. INSOLUBLE CRUSHED GRANITE - grit remains in the birds gizzard to help with digestion AVAILABLE IN DIFFERENT SIZES, DEPENDING ON SIZE AND AGE OF THE BIRD