Leaving aside the pest aspect (and I'm sure it's all too real in many places), rats are fascinating creatures with a sharp, pragmatic intelligence, loads of adaptability, and social behaviors that we primates can very easily recognize and relate to. I have seen rats perform clearly abstact thinking, brewing up complex ad-hoc plans, and show stunning degrees of spatial awareness. I have been lied to by a rat, who seemed to have worked out a decent model of my expected behavior. Which I promptly delivered - the rat won. And these were domesticated rats. I should be surprised if their wild cousins weren't up to even more hardcore mental trickery.