If robots end up becoming sentient and are not biological they won’t have evolved like we have being vulnerable to bacteria, diseases and poisons/toxins and because of it our sense of smell detects bad odors, we wash our hands, take showers and have a strong aversion to things that disgust us.

Robots may just happily pick up shit, dive in dumpsters and roll around in sewage. And why wash your hands or take a shower when water could hurt you? Who even knows if they would perceive smell the same way we do.