'Living plugs' smooth ant journey
A scientific study of the teamwork of army ants has discovered how they are prepared to let their fellow ants walk all over them to get the job done. The technique provided the rest of the group, which can number 200,000, with a faster route between prey and nest.
"The ants have a very large size range within their colony, measuring from 2mm up to 1cm (0.08-0.4in)," explained Dr Scott Powell, a biologist at the University of Bristol. "When the ants bump into a hole they cannot cross, they edge their way around it and then spread their legs and wobble back and forth to check their fit. "If they are too big, then they carry on and another ant will come along and measure itself in the same way. This carries on until an appropriately sized ant plugs the hole."
At this point, Dr Powell told the BBC News website, the ant becomes a "living surface" remaining in place for hours at a time while thousands of foragers walk back and forth across the trail.
"At the end of the day, when the traffic eventually diminishes, the ant that forms this motionless plug will detect that and pop out of the hole and run home," Dr Powell said.
The scientists found ant-plugged smoother surfaces speeded up the route from prey to nest and also increased the daily prey intake, which for army ants consists of other species of ants and other bugs.