Rhode Island Red Experiences

This is my first time having chickens and out of my four chicks - I have two RIR. I've read numerous mixed reviews on their temperament.

So far, out of my four - they are the ones that will fly at me as soon as I open up their brooder and I have been bite twice in the last 48 hours by them when trying to hold my hand out to them to pick up under their belly. They're about 6-7 weeks old.

Is this normal behavior for chicks at that age? Can anyone share experiences on their RIR chickens behaviors?