To make swimming more efficient, fish will follow a leader—even a robotic one—according to new research.

To understand what makes a leader among fish that school—or swim in synch in the same direction—scientists designed a robot fish to mimic the movement of a swimming fish.

They dropped the robot fish into a water tunnel with a school of golden shiners, a North American fish cultured in ponds. Not only did the fish accept the robot, they also allowed it to become the school’s leader.

The researchers found that once the robot’s tail started to flap and create a wake, or ripples in the water, the fish began to follow the robot. The robot fish’s wake eased the drag forces, or slowing effect caused by two surfaces rubbing together, on the fish. This made swimming easier for them.

In nature, school leaders beat their tails faster than the followers do. This has led researchers to believe that the followers are enjoying a swimming advantage from the leader’s efforts.

During the experiment, when the robotic fish started flapping its tail, the golden shiners slowed down their tails, displaying a behavior similar to that in the wild. Scientists hope to use robots to lead fish away from dangerous situations, such as toxic spills.

"By looking to nature to guide our design, and creating robots that tap into animals’ natural cues, we may be able to influence collective animal behavior to aid environmental conservation and disaster-recovery efforts," said Maurizio Porfiri, a professor at Polytechnic Institute of New York University.