'Living plugs' smooth ant journey

From BBC News:

Scientists from the University of Bristol observed that, when ants were foraging on rough terrain, some of them used their own bodies to plug potholes. They even chose which of them was the best fit to lie across each hole. The flatter surface provided the rest of the group, which can number 200,000, a faster route between prey and nest. The research, published in the journal of Animal Behaviour, said that the team first noticed the army ants' (Eciton burchellii) unusual behaviour in the insects' native rainforest home in Panama.

To investigate this further, the researchers inserted wooden planks, drilled with a variety of different sized holes, into the army ants' trails. They found that the ants did indeed plug the holes, but the team also discovered that individuals would size-match themselves to a hole for the best fit.

More here.