Hamster does not like new cage

Question
I recently bought an acrylic tank and wanted to transport my 1 y.o dwarf hamster from his smaller cage into this tank. At first he seemed to be quite curious about this new found larger space, but within 10-15 mins, he gets really nervous and anxious to 'claw'/'climb' his way out. I have indeed put his other belongings into this new tank with new & old bedding, but he still couldn't associate with the new space. I had to put him back into this old cage, and immediately he quieted down and slept.. A few days later I tried to set him in the new tank again but still with the same results, he gets excited for a while but he doesn't want to stay long.. I didn't insist because I'm afraid I might stress him out in the new tank.
I would like to know why did my hamster behaved this way? Is it age related? I dont understand why he chose his much smaller cage :( He's getting a little pudgy, and exercise alot lesser now. I thought a larger cage will make him move a little bit more..
He never had problem with me placing him in the playpen, probably he knew he'd go back into his old cage.

Answer
Hi Mandy

Sorry to hear that your hamster doesn't like his new home.  I'm not sure if there is an answer I can give to this problem.  I've had the same experience with some of my hamsters - some I have persevered with, others I've given in and returned them to their old cage.  It is obviously an issue for him and he feels safe in his old cage.  

I don't think that age is the issue - it is just that they have appalling eyesight and rely heaving on smell etc.  and the old cage obviously seems familiar to him.  I suspect that if you move him permanent into the new cage he might get the hang of it and calm down.  Really it is up to you whether to give in to him or persist.  I foster a lot of rescue hamsters and therefore they have to live in different cages.  Generally, I find that after a day they settle.  I usually leave them in the new cage and don't really disturb them for a day - let them find their way around, move their nest, etc. and by the following morning they are pretty settled.  Perhaps you should put him in his new cage and leave him on his own for a while to see if he settles down.

I hope you get on OK.

Regards
Sheila