Upon death, an ant will release a chemical, called oleic acid, that alerts other ants that the ant is dead. During this process, ants may also release pheromones. These chemicals are used by ants to communicate with other ants, and to signal food sources.
In addition to using pheromones, ants may also bury the dead. Ants are naturally social insects, and they want to make sure that they don’t spread disease or pathogens to other ants. This is one of the reasons why ants carry dead ants to a midden. The midden is a dumping ground for ants, and is found within the nest.
In fact, some ants will take dead comrades out of the nest and bury them. Ants will also move the dead away from the nest to a midden. This is called necrophoresis. Necrophoresis is a form of social distancing that limits cross-contamination.
Ants carry dead ants out of the nest because they have a strong sense of smell. Other ants may be attracted to the scent of the dead ant. If the dead ant is carrying food, ants will gladly eat it. The ants may also carry the dead ant out of the nest to prevent the disease from spreading.
Ants will also carry dead comrades out of the nest if they are injured. This is not done to soften the loss. Ants will also drag the dead comrade to a midden.
Some ants are able to find food even without the aid of pheromones. They may use dead insects to produce protein or fungi. In addition, they may use tiny leaf cut-offs to grow food.