I have 12 various chickens in my group and I am absolutely amazed an how much crushed granite they are going through. I put it in a container in their yard and it goes really fast. It also is amazing me because my feed store only sells it in small bags and it is expensize. Is it usual for them to just eat a pile of rocks if they don't actually need it? Just checking because I would have to say the granite is starting to be the most expensive thing I buy. I do leave it free choice in one of the chick feeders I had left over from when they were babies. They peck at it all the time. But then again, they eat the small pine shavings too. If you couldn't tell these are my first chickens and they are about 19 weeks old. No eggs yet and counting the days. I am expecting something in February if all goes well, and between the run the feed the supplies, etc, I will never make my money back in the the savings of not buying eggs at the store. Good thing I knew that going into this hobby.