Hamster accident

Question
Hi i got my dwarf hamster when it was yong. It bit me a couple of times then it stoopped and was a very friendly hamster. It now looks fully grown but might still be a bit smaller and young. Then this happened, it was on top of its house and I stuck my hand in to pick her up and she nipped my finger. I pulled away and she didn't let go on time which sent her flying off the roof of her house and she landed on her back. Ever since she has bitten any1 who tries to pick her up and she runs after ur fingers. I'm also a bit afraid of tryinfg to pick her up because she has drawn blood and it hurt. How can i solve this problem and is it possibly something like teething or is she just going nuts. Email me back and thank you.

Answer
Hi,
thank you for your question.
I've heard of this behaviour in dwarf hamsters (Winter White and Campbell) a lot and I had a Winter White Dwarf that did it, too.
Do you reach into the cage from above? If you do, I really recommend a cage you can open at the sides because anything that comes from above means danger for small animals like hamsters (birds of prey, bigger predators).

Does she bite when you just put your hand into the cage without trying to pick her up? Try to lay your flat hand into the cage far from her and let her come to you if she wants to. Don't move your hand, just let her explore. When she feels comfortable sitting on your hand, you can start to  take her out.

Or you can try to find a compromise, I did that with my biting dwarf (who jumped across the cage to bite me as soon as I reached in...). Offer her a cup or a tube and gently shoo her inside, then take her out. Many dwarfs just bite inside their cage and are perfectly friendly outside. I always took my dwarf out in her food bowl.

The reason why your hamster didn't bite at first can be that she was scared through the accident and is afraid of it happening again. But probably she's fully matured now and starts to defend her territory (dwarf hamsters are able to breed at the age of three weeks but are not adult until the age of two months).
I hope I was of some help to you
Jennifer