I was given 6 chickens from one of my buddies. 2 bantam hens and a rooster. 2 silver laced Wyandotte’s. 2 bantam hens and 1 silver died. I bought a rooster and 2 hens that are barred rocks from someone else. I have the bantam rooster away. Today, my wife text me and said the rooster was dead. They have access to clean water and food at all times. They are safe from predators. They have never acted injured or sick. Fine one day, dead the next. I have them on centipede grass in an area that was farmland about 6 years ago. I would think that’s long enough for any pesticide to be gone. Any idea why they would just be dropping dead?