Hamster bites all of a sudden!

Question
I just put my dwarf hamster in a new, roomier cage. I put all of the toys he
had in his old cage, his bowl, his wheel, and his house in the cage. His old
cage was a barred cage with a tube running up the back, and it was very
small. His new cage is a glass aquarium and it's much larger than his old one.
When he was in his old cage, I could put my hand by the door and he'd climb
onto it and let me pick him up, pet him, etc. Now if I put my hand in his new
cage, he bites me and won't even let me touch him! He's about 3 months old,
and I put him in a new cage last Wednesday. What could be wrong with him?

Answer
Hi Sam,

It could just be that he is trying to find out about his new territory and how far his boundaries are.

But, with the old cage you were only putting your hand near the door - not actually in his territory - and now the whole tank is his territory so he sees you as an intruder!

Also, hamsters reach maturity at around three or four months old so he might just be showing his true colours and how he is going to be once he reaches adulthood!

Just try going through the taming steps again from the very beginning and be very patience.

Kind Regards,

Tammy