Scientists used rat-sized robots to study evolutionary patterns over thousands of generations without them growing old in the process.
They programmed a small bots with the need to forage for batteries that he placed in the vicinity, as well as the need to "mate".
"The robots would obviously produce no offspring but the desire to mate allowed us to study how successful mating habits evolve," explained Stefan Elfwing of Okinawa Institute of Science and Technology in Japan.
This could provide a way for scientists to gather information about evolution much faster than before.
Each bot was equipped with a camera so it could locate mates.
A port used infra-red light to copy their genes when they found a suitable partner.
The robots used electrodes in their teeth to recharge once they found a battery.
Mating and finding batteries both tired the robots.
Elfwing found that 75 percent of the robots turned into what he called "trackers", or robots that actively sought mating partners.
The rest turned into "foragers", or robots that sought batteries and only happened to mate if their infrared port lined up with another port during their quest for more electricity.
Elfwing hopes his robots would help him explore other facets of evolution.