Across a broad, dry, sandy path, worn firm, some thousands of ants passing to and fro their nest had left a slight trail. They were hurrying on in full work, when I drew the top of my walking-stick across their road, obliterating about an inch of it. In an instant the work of the nest was stopped, and thousands upon thousands of factory hands were thrown out of employment. The walking-stick had left two little ridges of sand like minute parallel earthworks drawn across their highway. Those that came out of the nest on arriving at the little ridge on their side immediately stopped, worked their antennae in astonishment, then went up to the top of it, and seemed to try to look round. After a moment they ran back and touched those that were coming on to communicate the intelligence. Every ant that came did exactly the same thing; not one of them passed the little ridge, but all returned. By-and-by the head of the column began to spread out and search right and left for the lost track. They scouted this way and they scouted that, they turned and doubled and went through every possible evolution, hundreds of them, sometimes a score at once, yet not one of them attempted to go straight forward, which would have brought them into their old path. It was scarcely thrice the length of an ant's body to where their path began again; they could not see or scent, or in any way find out what was so short a distance in front of them. The most extraordinary thing was that not one ventured to explore straight forward; it was as if their world came to an end at that little ridge, and they were afraid to step into chaos. The same actions were going on behind the other ridge of sand just opposite, an inch away. There the column of ants that had been out foraging was met with a like difficulty, and could not find their way. There, too, hundreds of ants were exploring right and left in every direction except straight forward, in a perfect buzz of excitement. Once or twice an ant from either party happened to mount on the parallel ridges at the same time, and if they had strained forward and stretched out their antennae they could have almost touched each other. Yet they seemed quite unconscious of each other's presence. Unless in a well-worn groove a single ant appears incapable of running in a straight line. At first their motions searching about suggested the action of a pack of hounds making a cast; hounds, however, would have very soon gone forward and so picked up the trail.