Another mystery chick killer years ago that wasn't obvious at first also was cleared up when the original poster put two and two together and realized the husband's welding shop, adjacent to the chicken coop was releasing carbon monoxide that was infiltrating the brooder, killing the chicks.
These obscure causes are rare, and that's why no one thinks of them. But hopefully, this will trigger more ideas.
These obscure causes are rare, and that's why no one thinks of them. But hopefully, this will trigger more ideas.