Why do ants stop at each other when passing each other?

Answer 1

just for one and only reason that is communication
now let us take a look on the way of their communication

Ants communicate with each other through chemicals called pheromones, these signal messages are more developed in ant species than in other hymenopterans groups. Like other insects, ants smell with their long and thin antennae that are fairly mobile. The antennae have a distinct elbow joint after an elongated first segment; and since they come in pairs—rather like binocular vision or stereophonic sound equipment—they provide information about direction as well as intensity. Since ants spend their life in contact with the ground, the soil surface makes a good place to leave a pheromone trail that can be followed by other ants. In those species which forage in groups, when a forager finds food they mark a trail on the way back to the colony, and this is followed by other ants that reinforce the trail when they head back to the colony. When the food is exhausted, no new trails are marked by returning ants and the scent slowly dissipates. This behavior helps ants adapt to changes in their environment. When an established path to a food source is blocked by a new obstacle, the foragers leave the path to explore new routes. If successful, the returning ant leaves a new trail marking the shortest route. Successful trails are followed by more ants, and each reinforces the trail with more pheromone (ants will follow the heaviest marked trails). Home is often located by remembered landmarks in the area and by the position of the sun; ants' compound eyes have specialized cells that detect polarized light, used to determine direction.

Ants use pheromones for other purposes as well. A crushed ant will emit an alarm pheromone which in high concentration sends nearby ants into an attack frenzy; and in lower concentration, merely attracts them. To confuse enemies, several ant species use "propaganda pheromones", which cause their enemies to fight amongst themselves.

Pheromones are also exchanged mixed with food and passed in the trophallaxis, giving the ants information about one another's health and nutrition. Ants can detect what task group (e.g. foraging or nest maintenance) other ants belong to. When the queen stops producing a specific pheromone the workers raise new queens.

Some ants also produce sounds by stridulation using the gaster segments and also using their mandibles. They may serve to communicate among colony members as well as in interactions with other species

Answer 2

Ants communicate with each other through tappings with the antennae and smell. They are considered, together with the bees, as one of the most socialized animals. They have a perfect social organization, and each type of individual specializes in a specific activity within the colony. They are thought by many as having a collective intelligence, and each ant is considered then as an individual cell of a bigger organism.

http://www.bubblegum-productions.com/anthony/social.htm

Answer 3

Ant Stop

Answer 4

To get directions to the next ant hill.

Answer 5

Probably to see like..who it is. They all look a like so maybe they stop and are like "Do I know you?" Haha. I'm not sure. Thats an excellent question.

Answer 6

Maybe to stop and say a friendly hello?

Answer 7

communication