I'm concerned. My 12 babies are about 3-3.5 weeks old. Soemtimes they try to fly a lot, bumping into each other and landing on each other. They all do it so I'm thinking its normal even though I worry about the littlest who is a 10th the biggest ones size. Is this common? Do I need to trim their flight feathers? Do I need a bigger brooder pen? Seems the bigger it is, they more they try to fly. As a side note, the denominate rooster likes to perch on top of the water jug. Since then I've put a top on the cage. Silly rooster. Here's their outdoor pen. We spend about 30 minutes or more at a time outside when it's warm and sunny. They seem to love it. Oh. And I also notice how they sometimes puff up on each other - assuming this is a trait of finding out who's top in the group?