That's what it's called "Dumor poultry feed" it looks like tiny pebbles,what has me wondering what happened is they they were perfectly fine the night before peeping around this morning they woke up totally different. And died :/
It sounds like u have them adult feed, I don't think they are fully able to digest that. And if it was pellets that can't eat that, and if it was crumbles they just couldn't digest it