Grit is required as chickens do not have teeth. With grit, chickens can "chew" & breakdown feed so their body can absorb the nutrients they need to be healthy & produce larger eggs more consistently. As chickens do not have teeth, they need grit (basically little rocks) to help break down and digest their feed. Grit is rocks with nothing added. Specifically, 100% natural quartzite. Quartzite is a hard, non-foliated metamorphic rock which was originally pure quartz sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Grit is to be set out at all times for chickens. Chickens will eat as needed and will not overeat. Even if your flock is free range and finding grit in the yard, we recommend supplementing their feed with grit to avoid digestive issues that are common without grit.