All they need to do now is stap a mini harness to the rat and a small kite ( maybe filled with some helium ( kites and helium bring back old post memories) ) and film it.
You could probably sell the footage for some coin to a kite DVD company or mag.
Introducing " the Slingshot Rat Team " great publicity and the rats could live like rock stars.

Twisted idea I know. ( for the animal liberationist the harness could contain flotation for the rats as well )

I think I should start doing some work