At 2.5 years old, it seems like they should be well established, so the change in behavior is even more puzzling. Are you and your husband away from home all day? If so, is there any way you can put up a camera to watch what is going on around your house? It just seems the most likely that...
What type of neighborhood do you live in? Is it possible that other people could have gone up to your gate and harassed/teased/frightened your chickens? I'm astounded at how some people have no sense of people's private property/animals. I was just talking to a lady yesterday who said her...