It's gonna take some time for them to get used to you. TBH I'm not surprised at all that one of them nipped you >.< Are you new to the world of rodent ownership?

Oh heavens no, I've owned rodents since 2006, and have bred 'em... All I did was pick one up to move it to it's new cage ;3;. It was a small one [luckily, The big rat bites huuuurt.].

Ah >.< Then I very much trust you know what you're doing!

And yeah, it's good the bite was small >.< I've had a couple nasty bites from two of my girls, but in all incidents it honest to god wasn't their fault or intention. The first bad bite I got was when I was new to having ratties, and one had gotten surgery and needed to be housed separately from her sisters, so being a new owner/moron, I wanted to show the other two that she was doing okay. Well, they mobbed her with curious sniffing and trying to re-establish dominance, which terrifed her, so I reached in to get her, and she thought I was attacking her. She bit me literally to the bone in my right hand's pinky. I had to get stitches. So by the end of the day, she had her stitches from her surgery, and I had stitches to match! The other smaller but still needed stitches bites were during a period of homelessness last winter, and my girls (just two at the time, as my first girl (the one that gave me the bad bite) had passed away 2 months prior to my homelessness) were VERY upset from the couch hopping, so my oldest gave me 2 or 3 icky bites that broke the skin down to the fatty layers, but I never did go for stitches for those XD

SO YES, I don't blame them for biting me! It wasn't their fault in the first place, and I was never mad :3 Though I will admit it was quite scary to feel teeth on my bones and to be held in place like that for almost 30 seconds. But I ignored my own wound and just scooped her to her cage and made sure she was alright before I even began to give a shit about my own bite!

My first major bite was from an aggressive rat @.@. I was just cleaning up a cage and was fixing a ladder when she decided to grab my thumb and bite down as hard as she could. Never went in to get it looked at, but it hurt a whiiile after. I've been a bit jumpy around aggressive/new rats ever since... Sucks, but I learned my lesson lol. I also got bit right above my upper lip... That one hurt too, and I'm not sure why she bit me o-o. I still have a small scar to prove it lol. Oddly enough, the thumb bite hurt worse, might of been because she had tugged and went all the way through the thumb bite... No clue!

Yikes! I think that with your thumb it hurt more because our fingers are so incredibly sensitive, and if she went that deep there was definitely some nerve damage. I know it took a long time for my pinky area to stop aching after my bite. But how odd to have been bitten by your lip! Sassy little rattie, tsk tsk!

Personally I'm okay with aggressive or new rats. Two of my girls I rescued from an abusive pet shop, so I ended up having to rehab them from whatever abuses they suffered, and had to socialize them with people because they were so neglected. It took a long time, but it was worth it. It broke my heart when my first girl passed away, because she took the longest to help, and she was just coming into her own and being freed from whatever those monsters had done to her..