Inability to properly use neck is happening to individuals in my flock. We have 16 hens and by accident, 3 roosters. I thought that finding 2 hens that looked fine in the morning, in late afternoon huddled against something with quite a few feathers (hen colored nearby) on the ground meant one of the junior roosters injured them trying to breed when the main rooster wasn't around. However it has been really hot. Then 2- 2 1/2 mo old pullets showed puffed feathers moving poorly and listless the next day. I've been giving them all eyedroppers of water with electrolytes, but the two hens who weren't holding up their necks even, died after 2 days. The two pullets look better but they cannot aim properly to pick up food. If I open the beak and give them moistened pellet of (sprouted whole grain) bread or their own chick food moistened, they are hungry and want more. But when they try to peck on their own they mostly peck in the air. Obviously they are hungry but they are misjudging aim. When they were first looking poorly eyes were half closed more on one side. There are plenty of clean filled waterers, but I've noticed the birds walking around with their wings slightly lifted in an attempt to stay cool. Is it a combination? Heat and injury by rooster? roosters all in isolated coops now. I autopsied dead birds. No mites, no worms in intestines or trachea-