Dwarf hamster - worrying behaviour

Question
We got three dwarf hamsters a few months ago (all female).  About a month ago one disappeared for a couple of days, after searching we found it dead, buried in a corner, it had clearly been (mostly) eaten by one or both of the others.  Since then one of the others (the submissive one) has been displaying strange behaviour - she spends almost all her time running up and down one side of the cage, pausing at each side to stand on her hind legs for a second and then continuing - she does this for hours every night.  She will only let us pick her up for a few minutes before becoming very agitated and jumpy.  The other hamster seems fine.  They are housed in a wire cage with a wheel, chew toys, a house etc.  Before she displayed this behaviour she was very prone to chewing on the bars of the cage, climbing along the roof.  She appears to have gone insane, please help!

Answer
Dear Clare,
thank you for your question.
Your hamster is bored and/or the cage is too small. What she does is stereotypical behaviour and you need to do something quickly or she might keep up that behaviour all her life, even in a bigger cage.
Rubbermaid containers or old tanks make excellent hamster homes, as long as you have a lid (mesh wire) and as long as they are not higher than wide to ensure proper ventilation.

I recommend a 20 gallon so that you can put in a lot of bedding and toys, the hamsters must be able to avoid each other comlpetely (winter white and Campbell's dwarfs are not really social and you need to separate them when they start to fight seriously).

Scatter the food in the bedding and hide it in crumpled paper and cardboard boxes or toilet paper rolls. Offer them branches and twigs to chew (hazel, oak, beech, wollow, birch, apple, pear, as long as the trees are not trerated with pesticides). Cork tunnels make good toys, you can also get clay tubes (normally meant to store wine bottles) at hardware stores. Vegetables and leafy greens can be beaded on a piece of string so that the hamsters have to work for their food. All this will keep them occupied and will hopefully stop the stereotypical behaviour or at least keep it down to a minimum.

It's normal that they ate the dead hamster, by the way, most rodents do that.
I hope I was of some help to you
Jennifer