Why ants might be better at navigating than you

Have you ever arrived at a destination only to realize you have no idea how to get back to where you started? If so, I've got some bad news for you — ants are better at navigation than you are.

New research published in Current Biology looks at one of the most impressive ant navigational skills: their ability to navigate while walking backwards. 

What makes ants such great navigators?

Imagine you're an ant taking a large piece of food back to your colony. Now think about doing it while walking in reverse.

Ants have the incredible ability to separate the direction that they are going from what they are seeing.

They're excellent navigators while walking forward, too. Ants are able to travel far away from their nests and still manage to find their way back. Even if you devilishly put an obstacle in their way and force them around it, they still manage to get back onto their path.

How do you study how ants navigate backwards?

By doing exactly what any five-year-old would do — build a maze.

Researchers from the University of Edinburgh looked at a desert ant that lives in Seville, Spain. They found an active nest and put up a bunch of barriers to create a circuitous one-way route back to their nest.

I remember I used to do this with my hamsters: build a huge maze in the basement and see if I could train them to navigate it. But this group was more scientific about the maze I once built for my hamster, RainCloud. They made sure the barriers didn't impede the view of the ants; they also allowed them some time to learn the route.

How do you get ants to walk backwards?

That was, in a lot of ways, the easy part. The group simply baited the trail with pieces of cookie — the small pieces of cookie could be easily carried forward and that way the ant could rely on their view and visual cues to navigate back to the nest.

But give the ant a bigger piece of cookie? All of a sudden the best way for the ant to carry the loot back to the nest is to drag it while walking backwards.

One of the most interesting things that the researchers observed was that the ants with the medium-sized pieces of cookie would spend a lot of time dragging it (because that's easier), but then would rotate occasionally while carrying the food and sort of check in with the scenery to see if they were on track for navigation.

The ones carrying larger pieces of food with which they couldn't rotate, would drop the cookie, walk a few steps forward, take a peek, orientate themselves and then resume pulling.

This shows remarkable memory, planning and ability to visualize moving in the right direction while seeing the complete opposite scenery.

Another really cool aspect of ant navigation is that they have a celestial compass, which means they can navigate by the position of the sun in the sky.

How did researchers determine that ants have a celestial compass?

This has been known for a while and has been shown in all sorts of insects: even the dung beetle can navigate using the stars. What this work adds is how the ants defer to the celestial compass when needed. 

While the ants navigated through their maze, the researchers would occasionally try to trick the ants by making them walk through a funnel, providing something incongruous to what the ants are expecting. Every time the backwards walking ants would be forced through the funnel. they'd come out and almost immediately point towards the nest and start trying to navigate nest-ward. In other words, even if they are disoriented and removed from the visual cues that they have been relying on, they can reorient by looking skyward and figure out what direction they are supposed to go.

Think of that the next time you get lost in the mall...