Proper bedding for chicks

[OverEasyAcresSC]

I have week old chicks and 2 month old chicks, anyone have suggestions on what the best kinda bedding is to let them nest in and/or have on the floor of the chicken coop? Right now I have coquina rock on the floor and my 2 month old chicks are eating it! Is this ok or should I change the floor to dirt, sand or mulch?

 

[gamebirdsonly]

I like to use pine bedding.

 

[OverEasyAcresSC]

I like to use pine bedding.

Do you know anything about coquina rock bedding? The wild turkeys where I work at eat it all the time but I don't know if it's ok my chicks are eating it?