If you're concerned about how fast robotic technology is developing then this should set alarm bells off. Robots can now eat biofuel, drink dirty water and excrete the waste.

Called the EcoBot III or Bio-Regulation and Energy- Autonomy with Digestion or BreadBot for short, the self-sustaining robot developed by Bristol Robotics Laboratory in the UK can eat leaves, dirt and feces and then expelling the leftovers like a human does.

"Robots that eat biological fuels could find enough fuel almost anywhere," John Greenman, a scientist at the laboratory, told Scientific American. "There is organic matter anywhere on Earth - leaves and soil in the forest, or even human waste such as urine and feces."

The researchers have been working on EcoBot since it was just called EcoBot I and EcoBot II. The previous versions of the robot could eat the same items but they didn't have a way of releasing the waste. EcoBot I could be powered on E.coli bacteria as it ate refined sugar while EcoBot II could break down waste using sludge microbes. However the researchers found out that the two EcoBots didn't have a way of releasing the waste that they'd eaten and it was slowly poisoning the robots. The EcoBot III was able to solve this problem by doing what humans have been doing for millennia: pooping.

"EcoBot-III is a robot that collects its own food and water from the environment. It performs the task we design it to do, and at the end of the day, it gets rid of its own waste. It literally craps into its own 'litter' tray," said Ionnis Ieropoulos, a roboticist at the Bristol Robotics Lab.

The robots can keep on operating for 30 years as long as they have food to eat. You might be wondering where a robot that can eat and expel waste might be used but the robot has already received attention from NASA who want to use it for extended space travel. The robot could be sent with astronaut to missions to Mars where it can be used to break down the astronaut's feces.

Here on Earth the EcoBot could be used to solve sanitation problems in Third-world countries. The research team has already received funding from the Bill and Melinda Gates Foundation. The team is already working on new version of the EcoBot, the EcoBot IV. The new robot will be smaller and will have more stacks of microbial fuel cells to extract more power from the food it eats.