I have 2 Coturnix hens who are 10 months old. While they were somewhat skittish at times, at least one of them would eat out of my hands and "jump" for worms when I held them in the air. I was able to hold them without too much trouble, and they would even peep at me and come to the end of the cage when I talked to them. They were also very curious when I put anything new into the cage. Now it's winter and they've stopped all of this behavior. In fact, they think I'm going to kill them every time I even try to give them new food (they make a growling noise). If I try to pick one of them up, they nearly kill themselves screaming and running all over the cage! And forget about talking to them at the end of the cage anymore; they start making noises like I'm going to eat them. They aren't laying anymore and spend most of their day huddled together and not doing much else. It gets into the 40's here at night and I have a heavy blanket I put over the exposed parts of the cage when the sun goes down. I thought they were just cold, but I spent one day blowing a small space heater into the cage to warm them up and they didn't act that much differently. So is this normal, or is something wrong with my birds?