Ants on pavement
It seemed like these ants were finding a new home. Each one heading one way was empty handed. They went in to the ground under a plant's leaves. Each one heading the other way had what looked like an egg, and at the front of the line, they were milling around a larger ant, the queen perhaps.
I guess they would go to nest, well, the way ants generally act is union and work
Maybe they find a new nest for half the ants when the colony gets too large? I'm not sure
It was interesting to see though.