An example of the kind of important work done in rat self-control research might be Green & Estle's work.

Which demonstrated that the type of reinforcer can be an important variable in preference reversal as opposed to simply magnitude - a more typical research paradigm. Green, L., & Estle, S. J. (2003). Preference reversals with food and water reinforcers in rats. Journal of the Experimental Analysis of Behavior, 79, 233-242.