To me there's nothing outside of the norm there. At 8 weeks OOP, they are really young, put yourself in their "shoes" to see things from their perspective :
*They've been taken from their home, separated from their parents, put in a strange place with lots of weird sounds and smells they never encountered before...
*On top of that a giant creature is moving outside the place they've been trapped in and that giant even sometimes grabs inside... "what does this monster want? eat us perhaps?"
Knowing that, it's not surprising they just try to get on the opposite side of the cage when you are near, or that one of them try to scare you by crabbing, he is just scared to death. They just need some time to get used to you and see that you are not a threat ;)