What's the difference between a yurt and a hut? One's a better Scrabble word. What they have in common though is being a hamster magnet.
According to a hamster handbook I just read, jute appeals to them. I happen to have some jute lying around, maybe from the '70's. It smells like earthy hay, it's scratchy and stiff, and sheds all kinds of debris as you crochet it. It also polishes your crochet hook.
Preliminary test results:
1. Bob the tester says, "If you get a hamster and the cage doesn't come with the house, you should crochet a house for it. Hamsters love little houses."
2. It is stiff enough to work as a house. The corners curl a bit.
3. Aisha the hamster explored it right away, hung out in it for long periods (for a hamster), and kept returning to it.
4. The true test is if she nibbles on it lovingly. Also if she furnishes it with fluffy stuff and nuts.