As an operant psychologist I have taught a lot of rats to press a lot of levers. I have taught them using manual pen-and-ink operant boxes with rotating paper scrolls, with solid state electronic boxes, and with fully computerized ones. I have taught rats of all ages, breeds and temperaments.
I have even taught operant principles with Sniffy, the rat-emulating educational computer game. Mind you, I am actually not very good at training the virtual Sniffy. I have always felt that Sniffy is not much better at emulating rat's behavior than it was at reproducing its biology (Sniffy, referred to in the manual as "he", had no testicles.)
My suspicions about Sniffy's lack of authenticity as a rat are further supported by the fact that the latest version has a frelling mouse on the cover.