So this morning I go in to wish the chicks happy one week b-day and some of them are making a weird new noise. They are all very perky and eating, drinking, pooing great......... It sounds sort of like a tiny cough. It's so hard to describe. They don't seem sick. Eyes are clear, poo seems normal. I started using pine shavings last week for bedding (the big bag from TSC) and they are a bit dusty -could it be getting in their throats? They have been at the exact correct temp. -no drafts etc. Otherwise -perfect health. They are on medicated chick starter and water only. Am I being a nervous chick mom or do I need to worry?