It's normal to be worried about your kids being so aggressive. It sounds as though they are acting out their normal instinct to see who will really rule the roost.

I've seen my cats fight, chase and taunt each other too. There is nothing us humans can do to intervene or change this situation. However, Step in if one of your cats is being too aggressive (causing injury) to the other.

It will all work out in time. Be patient and let all of them know they are loved equally!