Why doesn't anybody like Landfill? Why do they step (very far) to the side when he passes by? He can't understand it. He's a really nice guy. He's always happy. He's good at his job, and he always does what he is told. Why, then, do his friends avoid him? This makes him very sad.

His comrades know the answer very well, but how do you tell a 'bot that he should clean his bodywork every once in a while, without upsetting him and making him think he's being insulted? It wouldn't help.