I have just a few chicks-----3 that hatched from my own eggs, and 10 others I ordered. 2 of the ones I ordered suddenly died after I had them a few weeks (around 7 weeks old). I didn't see any symptoms in them at all. A third from this group, looks smaller than the rest, it's eyes are seemingly stuck shut (no pus or drainage of any kind), and it's crop is pretty big and sems mushy. All the other chicks seem fine----eating, drinking and acting normally. The sick chick does eat and drink, in spite of the fact that it can't see---I've tried wetting it's eyes and gently opening them, but it doesn't help much. Any idea on what could be going on?