How Long Do Ants Live? What Happens When Ants Die?

How long do ants live?

The individual caste members of the ant colony live disproportionate life spans.  The queen ant can live up to 30 years.  The worker ants live from 1-3 years.  The males die as soon as they mate, giving them an average lifespan of a few weeks.

Why the Queen Enjoys the Longest Lifespan

The ant queen enjoys the longest lifespan because she is fiercely protected by her colony of worker ants.  She is placed at the deepest center of the nest, surrounded by her workers for protection. The worker ants are also the royal taste testers feeding the queen only food that they have eaten first. 

When danger strikes, the queen comes first.  Worker ants are prepared to remove their queen from a dangerous situation quickly.  For example, in the situation of a flood, the ants will quickly link together, building an “ant raft.”  The brood, the youngest colony members that include eggs, larva, and pupa, are extremely buoyant and placed on the bottom serving as the base of the raft.  They will then place the queen in the center and surround her with workers.

Worker Lifespans Are Variable

The queen of an ant colony has the longest lifespan of her colony, but the worker ant’s lifespan expectancy tends to fluctuate.  Research has indicated that it is not necessarily colony size that affects the lifespan of worker ants, but when they were born into the colony.

The queen ant’s job is to leave the colony where she was born, mate, and then begin her own colony.  Interestingly, the worker ants that she first produces to help establish the new colony are small and have an average life expectancy of 1.2 – 3.1 years.  Workers that emerge into an established colony are larger with a lower life expectancy of .85 – 3 years.

Ant Longevity Research

The actual estimates of how long ants live vary in the research literature.  According to Kuter & Stumper (1969), the longest recorded lifespan in captivity is the black garden ant (Lasius niger) queen at 28.75 years.  Their research also indicates that a worker ant can live for 7-8 years.

Field research conducted by Porter & Jorgensen (1988) estimates that the western harvest ant (Pogonomyrmex Owyhee) queen’s lifespan is 14-30 years.

More recent research conducted by Keller (1998) states that the queen ant can live up to 30 years, the workers 1-3 years, and the males survive only a few weeks.

What Happens When an Ant Dies?

Necrophoresis is a behavior practiced by social insects such as ants when a member of the colony dies.  Members of the colony pick up the corpse and carry it to a refuse pile.  But how do they know when a colony member has died?  Ants have chemical compounds that are recognized by fellow ants.  When an ant dies, these compounds cease to send out signals, which is quickly noticed by colony members.  The corpse carriers will recognize the death within 1 – 2 hours and quickly remove the body from the nest.

Interestingly, corpse-carrying ants remain outside of the nest after carrying a corpse to minimize the risk of exposure to a pathogen that may have killed their fellow colony member.  If they enter the nest to rest, they tend to stay close to the entrance.

Just as they lived life thinking only of the colony, ants that are close to death do the same.  Research has found that ants from small colonies will leave their nest to die in seclusion.  The behavior minimizes the risk of infecting the colony.

What Happens When the Queen Ant Dies?

A colony cannot exist without an egg-laying queen.  Ants can not eat solid food.  First, they gather food and bring it back to the nest.  They then chew up the food and place it on their larva.  The larva will digest the food for them and then secrete it as a nutrient-rich liquid.  This nutrient liquid is what they eat.  If there is no queen to lay eggs, there is no larva to digest food for the adult ants.  The colony will either die or dissipate.  But that’s not the case with all species.

A study on army ants revealed that though these species engage in serious turf wars with one another, if the queen of one colony dies, neighboring colonies will accept them in and treat them like family within days.

Indian Jumping ants won’t readily give up their colony without a fight either.  Female workers will fight each other for the position when their queen dies.  A few will emerge victors and will have the ability to reproduce.

Resources

Keller L (1998). “Queen lifespan and colony characteristics in ants and termites”. Insectes Sociaux. 45 (3): 235–246

Texas A&M Agrilife Extension
“Texas Imported Fire Ant Research and Management Project – Biology”

Purcell, J, Avril, A, Jaffuel, G, Bates, S, Chapuisat, M (2014). “Ant brood function as life preservers during floods”. PLoS One. 9 (2)

Kramer, Boris, Schaible, Ralph, Scheuerlein, Alexander (2016). “Worker lifespan is an adaptive trait during colony establishment in the long-lived ant Lasius niger”. Experimental Gerontology. 85: 18-23

Kutter, H. & R. Stumper. 1969. Hermann Appel, ein leidgeadelter entomologe (1892-1966). Proceedings of the Sixth International Congress of the International Union for The Study of Social Insects (Bern), pp. 275-279

Porter, S.D. & C.D. Jorgensen (1988) “Longevity of harvester ant colonies in southern Idaho”. J. Range Manage. 41:104-107

Choe, Dong-Hwan, Millar, J, Rust, M (2009). “Chemical signals associated with life inhibit necrophoresis in Argentine ants”. PNAS.  106 (20) 8251-8255; 

Diez, L, Le Borgne, H, Lejeune, P, Detrain, C (2013). “Who brings out the dead? Necrophoresis in the red ant, Myrmica rubra”.  Animal Behaviour. 86 (6):1259-1264

Chapuisat, M (2010). “Social Evolution: Sick Ants Face Death Alone”. Current Biology. 20 (3): R104-R105

The Harvard Gazette
“Orphan Army Ants Join Nearby Colonies”

Penick, C, Brent, C, Dolezal, K, Liebig, J (2014). “Neurohormonal changes associated with ritualized combat and the formation of a reproductive hierarchy in the ant Harpegnathos saltator”.  Journal of Experimental Biology. 217: 1496-1503