Male silk moths are highly attuned to the odor of female silk moths. When a male detects this odor, he begins a characteristic ‘dance’ designed to bring him into proximity with his paramour. During the first phase of the dance, he walks in a straight line. You can get the moth to forego the subsequent parts of the ritual (zig-zags and circles) by giving him another whiff of pheromone. In that case, he’ll surge straight forward for each puff of odor he detects. I think you can see where this is going. You can get a male silk moth to follow a straight path by giving him a series of puffs of female silk moth pheromone. Even better, you can get the moth to steer a robot for you.
Noriyasu Ando and his colleagues from the University of Tokyo, attached a male adult silk worm to a free-floating polystyrene ball. You can see the result below.
In both panels, puffs of pheromone directs the moth to steer its track-ball controlled vehicle toward the source of the odor. In the right-hand panel, the researchers have messed with the robot steering, making it continuously veer to one side. In other experiments, the front of the tiny car is covered, blinding the driver. Regardless of what the researchers threw at it, the moth was able to steer toward the pheromone over 80% of the time.
Ando, N., Emoto, S., & Kanzaki, R. (2013). Odour-tracking capability of a silkmoth driving a mobile robot with turning bias and time delay Bioinspiration & Biomimetics, 8 (1) DOI: 10.1088/1748-3182/8/1/016008.