We have had 2 of our 4 nine weeks old chickens die in the last week. We put them outside around 6 weeks away from the rest of the flock. We found one dead in the coop a few days ago and another died today. What could be causing this? They have a small coop that has a thick layer of hay. The coop is in the garden so they have open access to what ever vegetables are left in the garden. My mother in law says that is plenty of food for them, but I'm wondering if they need layer food as well? We are new to raising chickens and are clearly not doing a very good job. We have older hens that were given to us and they are doing fine.