[Silvi Hamster]

Hi, I could really do with some help.
I have had my dwarf hamster for around 6 months now, and I adopted her at 4 months (she is ten months old). I’m pretty sure she had bad treatment in her first home. Which may have something to do with the fact she keeps biting. I tried to tame her at first for around a month and made minimal progress. Then I became very busy and now for the past month or so I have been properly working hard to tame her. Every day I put her in her playpen (which I cannot fit into- is this a problem?) and I hold a treat on my palm for her to eat, as in theory, this is where she has got to after the last session. However she seems to reset all progress every time, and bites my hand when I place food in my palm. So I make a “bridge” with a gloved hand to the bare palm with the treats, and she climbs on no problem and takes the treat. After a few times of that, I remove the bridge and place my bare hand out with a treat. She takes it with no problem. However, she won’t get off my hand. She just bites it until I tip her off. The biting starts lightly but does get aggressive if I leave her too long. Then by the next day she will be biting again and I start over. I’m starting to lose hope. Is it a problem that I left it so long to tame her? Are some hamsters impossible to tame? I am doing what every website says but it just isn’t working because she just bites. If I let her bite me enough she would probably give up but I would be very injured. I am quite happy if she just isn’t tameable, but I just want to know because I’m worried she’s unhappy. I forgot to mention she isn’t scared or anything and she runs straight to my hand, only to bite it.
Anyway, I think this is super long, sorry! But any help would be greatly welcomed, especially your own experiences because I feel like I’m the only person with this problem.
Thanks, from Silvi’s owner