We have 25 St Run American chicks that are just a little over a week old now. I've noticed changes in their behavior and I'm wondering if this is a way to sex them? Roughly half of them are quieter than the rest, as well as doing more scratching, bedding down and roosting. The other half are much louder than the rest and are starting to 'challenge' others by bumping chests with heads held high (like the big roos do) and looking like they are trying to 'fight'. For the 25 chicks, they are in a 5 foot diameter brooder box set up with a red heat lamp bulb that keeps a cozy temp (now down to 90 degrees this week). It has two 2' long feeders and one two gallon waterer. They are still getting Super Vitamins in their water, but I plan to stop that this week. Just wondering if anyone else ever began to see sex-linked changes in their babies before they feather out to be males or females for certain.