I've not lost any chickens for years and, now, in the last week I've lost two - one was an Aracuana hen and the other was a black sex-link. Each had no wounds or any apparent cause of death -they were just dead. Both were on their sides and their legs looked like they were running -one forward and one back. I have around 30 chickens, 16 turkeys and 5 guineas. None are aggressive, they have lots of room, go outside daily and eat crumbles, scratch grain and some treats like popcorn or scraps. They were probably 2-4 years old.