Over the last 2 months I have lsot 3 chickens. They were all on the older side of my flock as in they were all in the 3 year old range. The first one, a slw, acted strange for about 3 weeks and then the last day would just squat when we entered the coop and died the next day. The next one, a red hen from the neighbor about 2 years ago, died fairly quickly as in she died within a couploe of days of noticing she was acting strange and squatting again like the other one. This last one, california white, was just sick a day before passing. They have pine wood chips for bedding mixed with DE and we added DE to their food as my DH did some research about possible worms. They have been on the same layer feed from the feed store. I know the only way to know for sure is to autopsy them but that isn't going to happen, just wanting to get some idea what is going on as I have 16 other chickens in the coop that I am worried about.