It was in the single digits this morning. I let the ducks out of their current coop (a large, converted doghouse) and walked them to their run as I do every morning. They did the same thing they did last night. Walk a few steps and then lay down. I noticed they were trembling. I got them in their run and now they're just chilling in their pond under the heat lamp I have. I'm really worried but everything I've read online says that they will be fine in cold temperatures as long as they have a dry place out of the wind which their house certainly is all of those things. It's going to drop below zero tonight and I just want to make sure they are going to be ok. How worried should I be? How should I interpret their behavior. It'd break my heart to know they are cold.