On the Saturday before I left Norfolk, we went into Norwich so I could buy a few things (example given, a large jar of Marmite). On our way back to the car we walked past the Norwich Playhouse, and parked outside was the Insect Circus.
We didn't have time to go in, but I did get some pictures of the van and they do have a website, which is quite charming if you don't mind insects.
I particularly like the art work on the posters, which you are apparently able to buy from the Insect Circuses ebay shop, except not right now for some reason. I shall be keeping an eye out for them though.