I'm sure I would have loved the series if I'd read it as a kid - I've always loved miniature worlds, like the descriptions of Stuart Little sleeping in a bed made from a matchbox - but somehow never came across it.

I can think of examples with rats and hamsters, but your basic point still stands.

I can't think of any with hamsters*, but rats, definitely! I was always quite fond of rat characters, actually, because they were usually a bit anti-heroish or at least grumpy sidekicks. I just feel like there's something about mice as spunky underdogs that comes up a lot in kids' lit??

* I do vaguely remember seeing a movie about hamster spies, but I feel like that doesn't count...?