Sun and memories help ants navigate backwards

 posted by | 23/01/2017

Desert ants rank among the best insect navigators in the world, and now a scientific study shows their navigational skills are even more sophisticated than previously thought.

Scientists have revealed how the insects – which walk backwards when carrying heavy loads of food – use the sun’s position and visual memories of their surroundings to guide them home.

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Ants were known to use both processes but, until now, these were assumed to be two separate reflexes that required ants to be facing in their direction of travel. Instead, researchers have shown that ants walking backwards will occasionally look behind them to check their surroundings, and use this information to set a course relative to the sun’s position. In this way, the insects can maintain their course towards the nest regardless of which way they are facing, the team found.

The findings suggest ants can understand spatial relations in the external world, not just relative to themselves.

The surprisingly flexible and robust navigational behaviour displayed by ants could inspire the development of novel computer algorithms – step-by-step sets of operations – to guide robots.

An international team of scientists, including researchers at the University of Lincoln and the University of Edinburgh, studied a colony of desert ants in Seville to see how the insects navigate when transporting different-sized pieces of food. Although they usually walk forward when carrying small pieces of food, ants often walk backwards to drag larger items to their nest.

The team sunk barriers into the ground to create a one-way route to the nest. They then gave ants either a small or large piece of cookie, and observed how they made their way home.

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Dr Michael Mangan, based in the School of Computer Science at the University of Lincoln, specialises in modelling the navigational behaviour of insects and explores how this can translate into cutting-edge robotics. Dr Mangan said: “These amazing animals navigate through complex habitats despite their tiny brains and poor quality eyes.  Here we show how a simple “peeking” behaviour allows homing ants to combine directional information from multiple. Revealing their navigational strategies could lead to development of new sensors and control systems for robots.”

The study was published in the journal Current Biology and it has been covered by media outlets around the world, including BBC News Online.

To read the full story, visit the School of Computer Science blog.