Aw, so my little baby boy isn't a baby anymore!
I never thought about the fact that it could be to do with that; thanks
A lot of his other behaviour makes sense now too; he's always in a hurry to get places and explore, so that's probably because he's hunting for a female :P And I only deep clean the cage every six to eight weeks anyway, so that's not a problem.
Might be a silly question, but do females exhibit the same sort of behaviour with regards scent marking? I've only ever had female hamsters before Hamilton and never noticed them behaving that way, though I was a lot younger when I had them so probably wasn't paying close enough attention.