Rat bites!

Question
My boyfriend and I recently adopted a very little young boy (5-6 weeks), and named him Indiana Jones.  We have had him for just about a month and a half.  He is growing nicely and is well on his way to a good size.  However, within the last few weeks, he has started biting, and relatively frequently.  The odd thing is that he doesn't bite hands, arms, ears, anything, except the face!  He has bitten my boyfriend on the nose, and me on the lips several times.  We haven't been able to decide why he is doing this.  

We have been attempting to teach him not to bite with a gentle thump on the head, a loud, stern "NO!" and putting him back in his cage immediately, but it doesn't seem to be making much of an impression.  Could he be biting because he wants to "assert dominance" (he is not neutered yet) or will he just grow out of this?

Answer
HI Sarah

No need to make enemies with Indiana Jones by a gentle thumping of his head and exerting negative energy toward him by being stern. This type of discipline is reserved for human children (minus the gentle head thumping...LOL) Rats will never learn this way. They learn through positive things such as rewards, like when you teach them to come when called, the way to get that to succeed is to give them a reason to come, and it better be a good one, because rats have more important in things to do and explore and heaven forbid you disturb their fun just to say hello. You wont get another response like that UNLESS you have good reason, such as a yummy treat on the end of your fingers!  Your boy is simply learning with his mouth. They also tend to like things that protrude or smell, regardless of the odor, be it sweet or sour.  Your boyfriends largest feature on his face is no doubt his nose, as with all humans, unless of course you have undergone serious collagen injections to your lips that have them blown up to epic proportions, your rat probably smells the last thing you had in your mouth, nuff said. :P

As for asserting dominance, he wont do that with you, not yet anyhow, and he still probably wont, but it would be a good idea to look into getting Indiana a buddy, because rats are very smart and very social animals and regardless how much time you spend with him, you are not there to share his meals or curl up with him in his hammock or groom him endlessly for 20 minutes like another rat would do. He needs to chase another rat and play wrestle with him and this would make Indiana happiest.  Two rats will not cost any more than just one. You still need a decent size cage for him, you still need to see a vet when he is sick, and one sick rat doesn't make two sick rats. In fact two rats are more healthy than one lonely semi neurotic rat that, as studies show, tend to become obsessive compulsive when they are solo which isn't very fun, either.  That said, in order to break the habit of being bitten, do not simply put him toward your face. He, for whatever reason he has, wants to bite his nose and your mouth because he smells food or the smell of your chewing gum or whatever.  
My 2 year old rat has a fetish with my eyebrows and eyelashes.  He pulls them and runs when I am laying on the floor and he comes up to me. I just push him away when I see him coming so he doesn't do it because frankly, it hurts, and he doesn't realize it does nor does he care, all he knows is he wants to pull them for whatever reason. Oh, and beware of your toes when you have socks on. I dont care who you are, almost every rat owner I know complains that their rat attacks and bites, playfully of course, but it still hurts, their toes, big or baby toes, they seem to think they are some kind of smaller animal hiding in the socks. NOTE TO YOU: WEAR SHOES OR SLIPPERS or pay the price! :)