Can Ants Live Without Their Queen?

Every ant colony has a queen. She is the mother to all of the ants in the colony, and that colony goes out of its way to protect her at all costs. But what if something happens to the queen? She is mortal after all; does the ant colony disappear when the queen does?

Ants live in eusocial societies. Being ​eusocial​ refers not just to the social structure of the colony, but to the relatedness of everyone in it. You see, the queen is the only ant in the colony that lays eggs, but she is not the only female in the colony.

While humans each have two sets of genetic material, and the information in those genes can determine sex, ants determine sex by how many sets of chromosomes they have. In this system, females have two sets, and males only have one. By the way, most of the ants you see crawling around are females. The males are typically smaller and have wings, and they don't do much more than mate and then die.

When the queen lays an egg, she places half of her genetic material in the egg. If a male comes by to fertilize the egg, it will develop as a female with two sets of chromosomes. If not, it will still develop, but as a male, with just one set.

This is a system called haplodiploidy, and it's the reason ants (as well as bees and termites) have such tightly knit colonies. Basically, it's like living in a city where the most distantly related citizen to you is a half-sibling.

Because the queen is the only egg-layer in the colony, one would assume she is ultimately vital to the survival of the colony, and this is true to an extent. If the queen dies, the colony will function just fine, but the problem is that there will be no new births because nobody is laying eggs anymore.

For a colony, this is not typically a problem. Queen ants can live for decades, as evidenced by laboratory colonies that have shown that queens can live up to 30 years. That means the queen can be around providing eggs to regenerate the colony for quite some time. Females, though, typically live for about a year, and males tend to live for roughly a week.

Because of these short lifespans, a colony lacking a queen won't last for long.

The good thing, for the queenless colony, is that they typically don't go very long without a queen.

When an ant colony becomes too big, new queens can be born. This happens in different ways depending on the ant species, but the result is that these news queens will strike out on their own, mate and settle down to form new colonies elsewhere. Sometimes, a new queen is born to a colony and she doesn't leave, creating a conflict that might allow her to replace the sitting queen.

If the queen dies without a replacement, though, the colony can be doomed – except for in at least one species, the Indian jumping ant. When the queen dies without an heir in a jumping ant colony, a remarkable thing happens. Some of the workers in the colony will undergo hormonal changes that cause their brains to shrink and their bodies to grow, all so they can battle for dominance in the colony. Once a replacement has won, she will assume the role of the queen while the other contestants revert back to workers.