I need confirmation that I am doing the right thing!

Question
QUESTION: I had a hamster (Angora) for about two years when I was in high school, and because I am now in an apartment, I bought a small Russian dwarf hamster on Nov. 30, after doing some research. I do not know the sex yet, but he/she is 5 1/2 weeks. I didn't think first before I bought the cage (I blame anxiousness) and I ended up buying one of those CritterTrail habitats, a decision I now regret. Seven (my hamster) constantly climbs the metal cage all the way to the top, burrows the plastic on the roof, and gnaws the cage. The water bottle that came with the set works poorly as well. It's only been three days or so, but I want to buy him a 20 gallon tank instead. Am I overreacting to be so quick to change his habitat? Also, will only three days of cage chewing ruin his teeth and give him brain damage? The pet store said they never even heard of metal cage chewing causing brain damage, and said it was perfectly normal.

Advice?

ANSWER: Dear Tanya,
thank you for your question.
You are definitely doing the right thing. It won't harm the hamster to live in the CritterTrail for a few more days, but they are way too small for any rodent. Gnawing the cage bars and burrowing in croners won't cause brain damage, but it will become a stereotypical behaviour fast and if the hamster is kept in a small cage for too long (a few weeks or so), he won't stop that behaviour even in a big cage. The teeth will be okay, they are made to chew hard things and even metal won't really damage them.
I hope I was of some help to you
Jennifer

---------- FOLLOW-UP ----------

QUESTION: Here is a follow-up:

I bought a new cage (a fish tank) with a wheel where he can't get stuck, as well as all kinds of homemade tubes. He seems to be having a good time and seems much more content. When I was fixing his cage a little in the morning, he started to try climbing up my arm, almost gripping my hand/wrist with his paws. He wasn't biting though.

What does this mean?

Answer
Most hamsters really enjoy time outside their cage no matter how big the cage is and will take any chance to get outside. Your arm is a good way outside and the hamster know that. He was probably gripping so hard because dwarf hamsters don't climb that well with their furry feet and he needed to hold on really well.