Ratty hormones.

Question
Hi,
I was just wondering if you could help me,
I am a 16 year old girl who owns two male rats.
A black and white hooded dumbo (Ralph) and a brown and white hooded rex (Oscar).
Recently Ralph has bitten me on my arm and 'puffed' his fur.
I didn't do anything different or hurt him.
He was just sitting on my lap.
The bite didn't draw blood, it felt like a pinch.
Not so long ago, I put my hand in the cage to clean
a part of the cage, I put my hands in the cage every night
so they are used to it.
Anyway, this particular time, Oscar bit me on my finger,
it hurt and drew blood.
Is there any reason for why he did this?
He hasn't done it since.
Also,whenever I stroke Ralph or Oscar, mainly Ralph, they won't leave my hand alone,
continually sniffing and then nibbling.
When they nibble, they are just nibbling the
surface of the skin.
Also, Ralph attacks Oscar and there
is constant squeaking coming from Oscar.
Oscar is constantly nervous of Ralph.
I'm aware that it could be his hormones as they are nearly 6 months old now.
What I want to know is will this eventually stop,
or get worse?
I've been thinking about castration for Ralph,
but I'm not sure if it will work, it is also a lot of money.
I can't separate them as I only have the one cage.  

Answer
How old are these boys? To me it sounds as if they're having hormonal issues due to puberty.. in which case, I recommend neutering, because thats pretty much your only solution other than separating the boys and watching your fingers. It could be due to a medical reason but given that both are doing it, I'd say its typical boy spats, their testosterone is flying.