At my place we're all well tuned to the sounds of troubled chickens that we hear during the daytime, and will dash outside to check on the situation when we hear those calls of distress. But twice now there has been a predator right in a chicken pen in the middle of the night, and they haven't made any sounds of alarm. The first time it happened I didn't go out to check until it was too late. This next time I knew better that what I was hearing could be trouble, and was able to catch the predator in the act. The sounds the chickens made were just a mild soft intermittent clucking, as if they were just saying to each other "move over you're hogging the roost" and didn't at all sound as if anyone was in any distress. Not at all the "fox in the hen house" kind of noise I'd think there should be. On the first occasion I was extra sleepy from an overworked schedule and didn't want to go out to check on what did not seem like a problem. But when the occasional clucking continued, I finally roused myself to check, and found that something had eaten some chicks and killed their Mama hen. This second time, when I heard that brief soft clucking, I recognized that it signaled trouble. Again, it was a predator, an opossum who was in a nest box, having eaten some eggs and having killed the Mama hen who was incubating them. Why aren't they making loud distress sounds? Because it's at night? Do they not want to attract attention to themselves in the dark? There have been other times when I myself have moved a brooding hen and then they make a special call that all the other chickens repeat, it sounds like a unique distress signal meaning "mama's getting hurt!" Why hasn't there been more noise when these Mama hens are getting killed defending their chicks/eggs? The roosters didn't get involved, neither vocally nor physically. They were perched up on the fence, well out of the way of trouble. What has your experience been? If similar, do you know why?