One of the things that we often say in our house is "I love all the people here. If you pick on someone I love, then I will have to correct you." The kids don't always get this at first. Rage and hurts get dealt out randomly and at the point of pain for these little ones.
As a parent what does this look like? Could look like many things. What I see the most is behavior that is brought on by simple kid things, "he touched my stuff" or "stop staring at me" turns into a rage issue because the threads of consciousness are tied to some real hurts.
When I see this, I make sure I look past the child's behavior into who the child is. Who are these kids anyway? I really can't answer that for you. They are all so very different. They are all covered with a protective layer of history and instinct. What I can say is that they have all learned to survive in a painful powerless situation. Now that you are nurturing them the poison is being drawn out, it must be felt and expressed.
Sometimes it will be shown with those small clinched fists, white knuckled and flushed skin. Maybe there will be tears maybe there won't be. Maybe those angry wet eyes are pointed at you. Every one of these is a moment to reaffirm who they are while building up the love of the home. They will love when they are first loved.