It sounds like something is different today than it was yesterday.  Did you smell like other boys when you picked him up today?  Or possibly like food?  Sometimes yummy smelling soaps will get that reaction, too.  Is he getting puffed up and aggressive looking before he bites or giving no warning?  

Where did you get him from, do you know his background and what was going on when he bit you? Just trying to work out his reasoning.

What do you mean by walking sideways?  Does he sort of put his butt out to the side and hop, with his fur puffed out?  If so, that's an aggressive move.  Rats do that to each other when they're not getting along.  

And yes, it's possible that the smell of another rat could do that.  Rats can be territorial, and if you just put him into a new cage, and you smell like other rats, he may think he needs to protect that territory from you...

Try to find the reason why he is biting. My Orion will nip for whatever reason (usually when we are playing with him or just gave him a treat) he often associates hands with food, but as soon as he realizes its our hand, he releases.

Has anybody told you why his balance is off? Is he well otherwise?

Most rats will bite anything that appears at the cage bars out of curiosity or because they think it's food. I certainly wouldn't recommend putting another rat to the bars. They may be fine without the bars between them.

Think back to the last time he bit you. What had you done before getting him out and what were you doing when he bit you?

Ok, more questions I'm afraid. Where is the door of the cage? Is it on top or on the side? Did you actually stroke him or did he bite you before you got chance? What colour eyes does he have?

My first thought is that you suprised him. Rats have very poor eyesight, especially albinos and if he didn't realise you were there before you touched him or you moved too quickly his initial reaction would be to bite - self preservation. I've heard of it quite often, although it does seem more common when the door is on the top of the cage.

If I'm right, I can only suggest that you make your presence known before you even open the cage. Talk to him and when he acknowedges you, then slowly try to touch him. If you're worried that he may bite you again try stroking him with some food, maybe a biscuit, then if he bites it doesn't hurt you and he thinks you've brought something nice!

Ok. So it seems like he is biting deliberately. I've just read right back  through the posts and it seems that you bought a 2 year old rat from Petco, right? I doubt that during that 2 year old period he was handled very much, especially given the reputation Petco has, so my second guess would be that he simply doesn't want to be touched because he was never socialised as a youngster. If I'm right then this may never change, given his age. You may have to accept that he's happier without you handling him. I've had a few like that. Even though you can't hold them you can still build a relationship with him though. Just try to make him like you and trust you. Move slowly and keep talking to him. Take him lots of treats and maybe just sit by his cage sometimes. Hopefully he'll begin to associate you with good things and start to come to you when you call him and climb on you when he's out, so long as you don't touch him.

If you need him out of the cage to clean him out or for playtime, wait until he's in his bed and lift the whole thing out. When it's time to go back, hold the bed in front of him and he should climb back inside. They catch on very quickly.

He needs more time to learn to trust you. The more you approach him like this he may continue to bite.......go slower.

I did it (kind of) ! I picked my least favorite hand, held it out for him, he bit me, but i stayed still. Then he craweled onto my hand, and bit me harder! Then he started washing himself for a LONGGGGG time. Maybe this is progress, but my hand hurts!

i agree with swub about some rats that just dont like to be touched i have one male named brat one of the sweetest gentelest rats i have only vice he really doesnt like to be touched he'll come up and sniff comes when hes called takes treats from my fingers ever so gently but what ever you do don't pick him up or pet him he squeels like your killin him i've tried every thing to get him to alow me to handle him i finaly gave up and excepted the fact that thats just the way he is.

THANK YOU SO MUCH FOR ALL YOUR HELP!!!   It WORKED! I just went for him after a few days, and he didn't bite, squeal, nip or ANYTHING!!! I have found that he LOVES being taken out, and he is a VERY sweet rat once you get to know him! Thank you SO much!!!!!!!!

that's great!