Imogen there are various threads with lots of tips on photographing hamsters
I know what you mean. But it sometimes means taking a lot of photos to get one where they are not moving! Food is useful for that. Set up what you want (eg a backdrop). Let the hamster explore the area and find a bit of cucumber. I have a lot of out-takes each time!
Lighting is the other thing. You need enough light so you can have a fast shutter speed to capture them if they move - rather than just get a blur. I sometimes just have an anglepoise lamp on if the light isn't very good. Not pointing right at them obviously. Or I hang a t shirt over it so it's not too bright but a lot lighter (be careful with that though and don't leave it on there or it could be a fire hazard.
Half the fun is thinking up a background or theme. Even a musical instrument could be a cardboard made one.