Scientists created a small robot to study how ants teach one another. The robot was designed to mimic the behavior of rock ants, which use one-to-one tuition, in which an ant who has discovered a much better new nest can teach the route there to another individual.
The findings, which were published in the Journal of Experimental Biology, confirm that the majority of the important aspects of teaching in these ants are now understood because the teaching ant can be replaced by a machine.
Tandem running, in which one ant literally leads another ant quite slowly along a route to the new nest, is critical to this teaching process. The pupil ant learns the route well enough to return home on its own and then lead a tandem run with another ant to the new nest, and so on.
Prof Nigel Franks of the University of Bristol’s School of Biological Sciences stated: “Teaching is so important in our lives that we spend so much time either instructing others or learning ourselves. This should make us wonder if non-human animals are capable of learning. In fact, the first case in which teaching was rigorously demonstrated in any other animal was in an ant.”
Teaching is so important in our lives that we spend so much time either instructing others or learning ourselves. This should make us wonder if non-human animals are capable of learning. In fact, the first case in which teaching was rigorously demonstrated in any other animal was in an ant.
Prof Nigel Franks
The team wanted to figure out what was necessary and sufficient in such instruction. If they were able to build a robot that successfully replaced the teacher, it would indicate that they had a good understanding of all the key elements in this process.
The researchers constructed a large arena to create a significant distance between the ants’ old nest, which was purposefully designed to be of low quality, and a new much better one that ants could be led to by a robot. A gantry was placed atop the arena and moved back and forth with a small sliding robot attached to it, allowing the scientists to direct the robot to move in straight or wavy lines. Attractive scent glands, from a worker ant, were attached to the robot to give it the pheromones of an ant teacher.
Prof Franks explained: “We waited for an ant to leave the old nest and put the robot pin, adorned with attractive pheromones, directly ahead of it. The pinhead was programmed to move towards the new nest either on a straight path or on a beautifully sinuous one. We had to allow for the robot to be interrupted in its journey, by us, so that we could wait for the following ant to catch up after it had looked around to learn landmarks.”
“When the follower ant had been led by the robot to the new nest, we allowed it to examine the new nest and then, in its own time, begin its homeward journey. We then used the gantry automatically to track the path of the returning ant.”
The team found that the robot had indeed taught the route successfully to the apprentice ant. The ants knew their way back to the old nest whether they had taken a winding path or a straight one.
Prof Franks elaborated: “A straight path may be faster, but a winding path allows the following ant more time to learn landmarks and find its way home as efficiently as if it had been on a straight path. We were able to compare the performance of the ants that the robot had taught with those that we had carried to the new nest site and had not had the opportunity to learn the route. The taught ants returned home much faster and with greater success.”
The experiments were conducted by undergraduates Jacob Podesta, who is now a Ph.D. student at York, and Edward Jarvis, who was also a Masters student at Professor Nigel Franks’s Lab. The gantry programming was accomplished by Dr. Alan Worley and all the statistical analyses were driven by Dr. Ana Sendova-Franks. Their approach should make it possible to interrogate further exactly what is involved in successful teaching.
