A swarm of more than 1,000 miniature robots has been revealed by a team at Harvard University in the United States.
The Kilobots can arrange themselves into a variety of shapes on demand.
It's very unusual to see this many swarming robots working together because coordinating so many devices is very difficult.
The Kilobots work together to form shapes, taking turns to move into position. If a traffic jam forms, nearby robots sense the problem and work around it.
"Increasingly, we're going to see large numbers of robots working together," said Radhika Nagpal from the Harvard School of Engineering and Applied Sciences.
"Whether it's hundreds of robots cooperating to achieve environmental cleanup... or millions of self-driving cars," she said.