Desert ants generally scurry around at high speeds whilst foraging to limit their exposure to the life threatening conditions of their habitat. Climbing over or crawling beneath obstacles means that ants do not have to make large detours to go around them.
"We found that the ants visually assessed the height of the barrier and learned how to lower their body enough to crawl under without stopping", explains Tobias Seidl, "When the barrier was made invisible to them, they had to use their antennae to examine it".
The researchers motivated the ants to run back and forth by placing biscuit crumbs flavoured with melon and tuna at one end of a channel. They observed the ants' reaction towards a horizontal barrier placed between the food and the ants' nest using high speed video recordings from the side. They then tracked the ants' movements and did a kinematic analysis of the results.