Imagine that you’re driving along a country lane. As often happens, the road suddenly transforms from a well-paved street to a pothole-ridden nightmare. As your suspension and your stomachs start to tire, your friends in the back suddenly force you to stop the car.

To your amazement, they jump out and lie across the potholes, beckoning you to drive your car over them. It may seem like a far-fetched scenario, but if you were an army ant, such selfless behaviour would be a matter of course.