Ants are fascinating insects that live in large colonies. Most people recognize that ants are smart, but just how smart are they? Do ants know if other ants die? What happens when an ant dies? Do other members of the colony carry their dead away and, if so, what prompts them to do this? Keep reading! In this article, we’ll answer these and other questions.
What You'll Learn Today
How Long Do Ants Live?
The average lifespan of an ant can vary depending on the species, as well as whether the ant in question is a queen, a female worker, or a male.
Queen ants live the longest and may live up to 100 times as long as similarly-sized insects. They can live for up to 30 years.
Female worker ants make up the bulk of each ant colony. Depending on species and environmental factors, they often live anywhere from one to three years.
Male ants exist only to mate with the queen and, as such, have relatively short lifespans. They typically live for only a month or less.
What Happens When an Ant Dies?
Ants typically die without much fanfare. They are sometimes killed or eaten by predators, but those that die of natural causes simply lay down and die.
They often end up on their backs, with their legs extended upward. Or, they may end up on their sides with their legs curled up.
When an ant dies within a colony, it may go unnoticed for up to two days. Other ants may walk right by the dead ant and take no notice of it.
During those first two days of death, the ant slowly undergoes chemical changes as its body begins to break down.
These chemical changes seem to be what triggers the living ants in the colony to take action. They will locate the dead ant and remove it to an “ant graveyard” of sorts–a pile of other dead ants.
There, the dead ants continue to decompose over time with the help of microorganisms. As more ants die, living ants bring them to the same pile, which is well removed from the living ants in the colony.
Do Ants Know When Another Ant Has Died?
Since living ants remove dead ants from their nest, it would appear that they know when an ant has died.
But they don’t remove the dead ants right away. As noted, they may pass right by a dead ant without ever giving it a second glance.
So yes, ants know when other ants are dead–but not necessarily at first. They may not recognize that an ant has died until it begins decomposing.
How Do Ants Know Another Ant Is Dead?
Ants have large eyes and can see well, but this sense of sight doesn’t appear to be helpful when it comes to letting them know that an ant has died.
They undoubtedly see dead ants lying around in the colony, and yet they don’t remove them until a day or two later. As mentioned, this suggests that they don’t know an ant has died right away, even when they can see the dead ant plainly.
So, how do the living ants know when an ant has died? What signals to them that the dead ant needs to be removed?
Scientist Ed Wilson did some significant research on ants in the 1950s. Through his research, he discovered that dead ants release oleic acid, a chemical which is also produced when butter or milk products begin spoiling.
To prove this theory, he placed a drop of oleic acid on a live ant. The next ant to pass this ant picked it up and carried it, kicking its arms and legs, to the “ant cemetery”.
The ant tried to rejoin the colony several times, but was carried back to the pile of dead ants again and again until it had managed to clean all of the oleic acid off of itself.
You can hear Ed Wilson explaining the experiment in his own words in the following video:
Why Do Ants Carry Their Dead Away?
At this point, you may still be wondering: why do living ants behave as they do? Why do they carry away dead ants from their colony?
This removal of dead ants is a necessary step in keeping the rest of the colony safe and healthy, as a dead ant can become a host for dangerous microorganisms that can, in turn, make the living ants sick.
It is possible that the dead ant doesn’t decompose enough within the first couple of days for this to be a problem. After all, it is the ant’s decomposing and releasing oleic acid that signals to the other ants that a dead member of the colony needs to be removed.
It’s possible, too, that ants find the smell of oleic acid to be off-putting. This may be the instinctive trigger that compels them to remove the dead insect and, thus, keep the colony clean.
Ants tend to ignore dead ants for the first day or two; after that, they will remove them to a pile of dead ants away from the colony. This suggests that ants do know if other ants die, but they may not recognize it until the dead ants begin releasing oleic acid.