Should I be worried? My girls are 9 weeks old three of them (RIR, Red Star, EE) are starting to make these noises that sound like my kids when they had croup - or like a crow, or a duck. Basically it sounds like, "quack quack quack". Then they go back to peeping. Is this normal, or could it be a respiratory illness? The only thing that has changed is that I got new bedding that was labeled "wood shavings" and the guy at the store was only "pretty sure" it was mostly pine. My (former) roosters didn't make this sound. Thanks for any help!