This thread makes me think of all my rats I've had. I'm not allowed any now as I'm at uni.
It's really interesting how rats have really taken off as pets, when I first got one of mine there was nothing you could buy for them, I had to make tunnels etc using cardboard tubing from carpets as everything was too small and designed for mice.
A couple of my rats used to get a little carried away when they thought my hand was food, they would grab it and bite it then realise and lick it instead. We used to let them wonder all around any room we were in, they were out between 4 and 8 hours a day. I regularily took one of them to supermarkets and even on a paper round in my armpit. Every so often she would come up and peek over my collar and scare some poor person witless.
Ill post some pics a little later.