Lions, tigers... carniverous robots oh my!

I heard about this through SolidSmack. (the blog/newsletter of solidworks)

"This one grabs flies, mice or other small creatures, scrapes them into a microbial fuel cell vat of bacteria that breaks down the biological material into pure robot-loving energy. No word on if the vat removes the fibrous material or if it’s dishwasher safe." - SolidSmack

"They can gain energy by chomping on flies and mice…The pests are lured in and digested by an internal microbial fuel cell." – New Scientist

How do I feel about this? Awesome. It's one small step closer to reducing our reliance on current fossil/electric fuels and a closed loop system. Could this work with biologic waste products? Why not right? To bad for the insects for now though.