I had 4 7 week old cochin chicks and 2 7 week old silkies. The cochins came from the same flock the silkies we raised from when they were 4 days old. We lost 2 of the cochins and one of the silkies last night. There are no apparent wounds, they had food and water...any ideas what might have happened to them? We just got the 4 cochins on Monday. They are contained in a fairly large cage, but when we go out, they are able to be out.