Yesterday, when I went to check my chicks, I noticed a strange rounded, yellowish thing with spots on it. I realized it was an egg and so I took it in. I found out that one of my eldest chicks laid it even though she isn't a complete adult yet (turning 6wks in a few days). I know for sure which chick laid it, and now she's turning a little more aggressive on her hatch-mates, by coming near them and pulling on their feathers. She only does it occasionally, but I don't understand why. Is it because pecking order is being established? She's the biggest out of the lot, and the heaviest (she eats a lot, just like her mother did before.) But ever since she laid that egg, she's been acting like the boss of all the others. (Here she is) Thanks in advance.