Our hamster is huge. He's really big. We just had to get him a bigger cage because he could reach the roof of his old one without even stretching, and that was just a standard hamster cage. The new cage is one of those three tier things with the tubes to climb up and down. Problem is, he's a bit of an idiot and won't use the tubes to climb up and down. I think it's because he's a little big for them, although I've seen him use them occasionally so he does fit through them. Instead, he chooses to fling himself off the top floor of the cage. I'm really concerned he'll break a leg or something doing this.
Considering suing the pet shop for false advertisement - he has to be part guinea pig or something 