I have 4 chickens, 8 and 9 weeks old. The chicken run is not finished, so they stay in the coop and we bring them out for supervised yard time. I feed them when I get home from work at noon (It is very dark and they are asleep when I go to work), and they always have 1/2 their feeder still full of crumbles and plenty of water. When I open the door, they attack the new food like they've never had any, and eat for a good long time. What's the deal? Why wouldn't they eat all the food instead of "starving" once the "fresh" food is gone?