Here is how ants reach home after walking backwards when carrying heavy loads of food

We all are aware that insects such as ants walk backwards with their tiny set of legs when they carry heavy loads of food. But have you ever thought how do they reach back home? Well, a new study suggests that ants use the position of the Sun and visual memories of surroundings to guide themselves back home.

The study also found that the navigational skills of ants are more sophisticated that thought previously.

The surprisingly flexible and robust navigational behaviour of the ants could be an inspiration for the development of new computer algorithms, step-by-step sets operations, to guide robots.

It was believed earlier that both processes were used by ants, but these were assumed as two separate reflexes that required them to be facing in their direction of travel.

Researchers said that this allows the insects to maintain their regardless of which direction they are facing.

Ants can understand spatial relations in the external world apart from those relative to themselves, the findings suggest.

A colony of desert ants was studied by scientists including those from the University of Edinburgh in the UK. They wanted to find out how the insects navigate when they transport different-sized pieces of food.

When carrying small pieces, they walk forward but ants often walk backwards to drag larger items to their nest.

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

Previous research has shown that ants walking forwards find their way by comparing what they see in front of them with visual memories of the route.

The team found that ants traveling backwards instead use the Sun's position in the sky to guide them.

Researchers observed that ants set off in the wrong direction when a mirror was used to alter their perception of the Sun's location.

To ensure they stay on course, backward-walking ants also routinely drop what they are carrying and turn around.

They do this to compare what they see with their visual memories of the route, and correct their direction of travel if they have wandered off course.

"Ants have a relatively tiny brain, less than the size of a pinhead. Yet they can navigate successfully under many difficult conditions, including going backward," said Barbara Webb from the University of Edinburgh.

"Understanding their behaviour gives us new insights into brain function, and has inspired us to build robot systems that mimic their functions," she said.

The study was published in the journal Current Biology.

(With inputs from PTI)