It seems that robots are becoming more and more human-like. A while back, scientists engineered robots that could feed off biomass (microbial fuel cells), now they are rolling out bots that can also defecate. Ecobot III is the baby of Chris Melhuish, director of UK-based Bristol Robotics Lab and Ioannis Ieropoulos, Research
Fellow at the University of the West of England. Ecobot III can survive for up to seven days, autonomously
feeding itself and going to toilet, so to speak, every 24 hours. The synthetic digestive tract in Ecobot III is
basically a gravity-fed pump that works like the human colon, applying waves of pressure that squeeze waste matter out of a tube. This prevents things from clogging up – just like a human.
[No image available for this one so here is a video of Stewie directing the robot what to do]

At present, Ecobot III is only able to extract 1 per cent of the chemical energy available in the fuel cells it ingests, but researchers are planning to explore how the robot will manage more substantial meals – namely, flies. Ecobot III will be presented at the Artificial Life conference in Odense, Denmark, in August.
[Newscientist]