Strange behavior..

Question
My dwarf hamster is just one years old, and it has shown some strange
behavior for the last few months. It is gnawing its foot like it's
obsessed, although it doesn't seem that this is hurting her.. Went to a vet
about it, they said she was fine. In the same obsessive way, she's
started licking the bars on one place of the cage for hours (no, we haven't
been feeding it there). The worst is that she's been starting to bite,
although she has been really tame from she was little. And not startled
"i'm scared" biting, no.. more like "calmly walking up to the hand,
jumping into it and biting till the owner bleed".. Quite aggressive, or
perhaps irritable is a better word. She will go out into my hand and bite
me, and then- after i've put her back into the cage, try to get out to
bite the hand again, kind of wasp mentality!

By now I'm probably more scared of her than she is of me. She will come
to me when she is out of her cage, but only to bite me!
I've had four hamsters before, so i recognize the "scared- bite", and i
don't smell of food. The vets didn't say anything was wrong with her,
and they took all sorts of tests.. So well, do you have any idea what
this might be? Or how to fix it? She has been quite nevrotic from she was
little, but if only I could stop the biting I'd be able to live with
everything else. By now the ordinary advice of "putting the hand slowly
into the cage to let her smell you" is a suicide mission.. She is not
acting scared or timid in any way, just really OCD with a sadistic
streak. Please help.

Vivian  

Answer
Hi Vivian,

You didn't say wether or not there are any other hamsters in the cage with her as this aggressive behaviour are very common signs of pregnancy, although i'm sure the vets would have picked up on this.

The only other explanation i can think of is a case of phantom pregnancy, which although rare can occur in all animal species. her age would also back this up as it is at about 1 year old where hamsters come to the end of there breeding period and she becomes sterile. she is become very territorial about her body and her cage, as this kind of biting is her way of saying 'stay away, this is mine'. dwarf hamsters when living as groups live with a pack mentailty and maintaining a hierarchy in the cage is common. she may be trying to display this behavior with you. does she go up on her hind legs when you go to put your hand in the cage? this could also be a sign of her trying to show her dominance. other than these reasons i can't think of any other reason why she may be acting this way. i would suggest leavung her alone for a month or so and let the hormones associated with her becoming sterile settle down. if this problem continues to occur after the month is over, get back to me, i will research this more and present you with another answer should the problem continue.

I'm sorry I couldn't have been more help, and i do hope this problems resolves itself. Best of luck and please keep in touch. thank you for your question.

Joanne x