Hello there and welcome to BYC!
Yes, when chickens are crammed in, sometime they do go off on each other. And sometimes they have a ton of space and they STILL pick on each other! If you continue to have issues, don't be afraid to cage a meany sometimes when they are most cranky. Pinless peepers work well too. I have had to resort to peepers over the years for aggressive birds that just won't behave. Aggression is common in many flocks. Some people cull the aggressive birds or rehome them. Caging them is an easy option or complete isolation for about a month. The aggressor returns to the flock as if they were a new bird and many times gets knocked down a few notches of the pecking order.
Good luck with your babies and welcome to our flock!

Yes, when chickens are crammed in, sometime they do go off on each other. And sometimes they have a ton of space and they STILL pick on each other! If you continue to have issues, don't be afraid to cage a meany sometimes when they are most cranky. Pinless peepers work well too. I have had to resort to peepers over the years for aggressive birds that just won't behave. Aggression is common in many flocks. Some people cull the aggressive birds or rehome them. Caging them is an easy option or complete isolation for about a month. The aggressor returns to the flock as if they were a new bird and many times gets knocked down a few notches of the pecking order.
Good luck with your babies and welcome to our flock!