Scientists have identified a specific chemical compound produced by naked mole-rat queens that suppresses reproduction and aggression in colony members, while a separate observation documented a rare example of peaceful queen succession in a laboratory colony. These findings, published in two independent studies, add to the understanding of social dynamics in the eusocial rodent species.
Queen Pheromone Identification
A study published in Nature identified isopropyl myristate (IPM) as a pheromone produced by the reproductive queen of naked mole-rat colonies (Heterocephalus glaber). Researchers analyzed hundreds of volatile compounds from over 350 mole-rats and found that IPM was consistently abundant in queens and nearly absent from non-breeding individuals. The compound was also detected lingering in colony tunnels, likely spread by queen patrols.
Non-breeding females exposed to IPM showed increased prolactin levels, a hormone known to inhibit fertility. In experimental conditions where queens were removed from colonies, daily application of IPM maintained social stability for three months, with stable progesterone levels and no observed pregnancies or succession battles. When IPM application ceased, conflict and queen succession followed.
IPM is undetectable to the human nose and is also a common ingredient in cosmetics.
The finding suggests convergent evolution of queen pheromones in mammals and social insects such as ants and bees. Researchers noted that understanding these mechanisms may inform future biomedical research on aging and cancer, as naked mole-rats are known for their longevity and cancer resistance.
Peaceful Succession in Laboratory Colony
A separate observation, published in Science Advances on April 15, documented a naked mole-rat colony at the Salk Institute for Biological Studies in San Diego that underwent a peaceful transition of reproductive queens in 2025.
The colony, named "Amigos," was established in 2019 with a founding queen named Teré, her male consort, and initial offspring. The colony grew to 39 individuals before newborn mortality increased, possibly due to overcrowding. In 2021, researchers created a separate colony, "Amici," with 20 individuals to reduce density.
In 2022, a laboratory construction project required moving the colony to a different facility. Following the move, Queen Teré ceased reproductive activity for approximately one year. During this period, two of Teré's daughters began growing larger and reproducing. One died from internal injuries; the other, named Arwen, became the colony's sole birthing queen. The succession occurred without observed aggression.
Researcher Shanes Abeywardena stated the peaceful transition was unexpected based on prior scientific literature.
Teré continued protective and guarding behaviors toward the colony, including Arwen, after ceasing reproduction. At approximately seven years old, Teré remains the largest individual in the colony.
Variability in Colony Behavior
The observation of peaceful succession contrasts with typical laboratory and zoo observations since the 1960s, which generally show new queens emerging through aggressive conflict.
Concurrently, a naked mole-rat colony at the Smithsonian's National Zoo in Washington, D.C., experienced prolonged aggressive conflict over queen succession for over two years, according to curator Kenton Kerns. Kerns also noted that an older, previous colony at the zoo had multiple queens breeding simultaneously without conflict. Kerns stated that human understanding of naked mole-rat behavior evolves and early assumptions may have been based on limited observations.
Biological Notes
Naked mole-rats are subterranean mammals native to East Africa. They are unusual among rodents for their longevity, with lifespans exceeding thirty years. They exhibit eusocial colony structures typically featuring a single reproductive queen and non-reproductive workers. They are mostly hairless, lack the ability to thermoregulate, and show resistance to certain diseases, including cancer.