Can't really tell anything about the darker chicks with their heads down. The better the pictures posted on "what breed or gender is this," the better the chances for accurate assessments.
Looks like you might have a Barred Rock, a Black Australorp, a Rhode Island Red, Buff Orpington and possibly a Silver Laced Wyandotte. BUT....I am not that good with chick ID so you will do well to post this pic in our What Breed section of BYC. Kelsie has left you with the link.