Researcher Ryan St. Pierre from the University of Maryland created a tiny robot, smaller than an ant’s head, and released a clip of the robot running surprisingly fast for its size, reported IEEE Spectrum.

The robot is 2.5mm long and weighs only one milligram – greatly smaller than a grain of rice. This size is too small to support the usual motors, thus St. Pierre embedded magnets in the robot’s hips. He then created a rotating magnetic field around the robot to force the embedded magnets to rotate and move the bot’s legs.

With the help of this movement technique, the robot was able to run up to 37.3mm/s, equivalent to 14.9 of the bot’s body length every second. For comparison, a cheetah can move at a speed equivalent to 16 body lengths per second, explained Futurism.

Moreover, robots this size can be very useful to potentially help deliver drugs in human bodies in places difficult to reach. Though this application still seems very far off, but St. Pierre’s near-term goals of figuring out how legged robots case usefully move at small scales can be a step forward, wrote IEEE Spectrum.