Sewer Rats and Super Heroes

Last night the Island Girl came and told me that their bathtub wasn't draining. So this morning, armed with long skinny pliers, I go in to see what's clogging the drain. There, shoved down the drain, are Super Man and Bat Man. Hmm. I ask the Youngest Island Boy if he put the toys in the drain and he tells me yes. I tell him that he can't put things down the drain and he says "But Mom they have to go down the drain to fight off the sewer rats!" I tell him that we don't have sewer rats and he says "How do you know?" I tell him that I've never seen sewer rats so we don't have any. He looks skeptical and says "Well if you haven't seen them - how can you be sure we don't have any?" I'm just sure and Bat Man and Super Man need to stay out of the drain. He looks at me like I'm in denial and walks off. Maybe it would've helped if I had told him that we have a septic tank and aren't even on a sewer line LOL