howdy all, I have been doing some reading and thinking (I know, I know not good to think to hard) and was wondering; why buy grit when there is gravel roads with sand! why cant one screen out the big stones and leave the sand like substance. would that be OK for them? If you think about it years of old they never bought grit from the store, the chickens would peck at the driveway. Just curious on every ones opinion!