Hello
and Welcome To BYC! X4, it is probably the pecking order working itself out as young as your birds are, both cockerels and pullets will spar and jump at each other. You may want to post good closeup pictures of your chicks on the What Breed/Gender forum for help with figuring out what gender you have https://www.backyardchickens.com/f/15/what-breed-or-gender-is-this
