Ants don’t have sexual orientations the way humans do, but same-sex sexual behavior absolutely occurs among them. Scientists have documented mounting, genital contact, and other sexual interactions between same-sex pairs across many insect species, including ants. The question is less about whether it happens and more about what it means in a creature whose brain is smaller than a pinhead.
What Scientists Actually Observe
Same-sex sexual behavior (SSB) in insects is widespread. A large systematic review found that nearly 90% of all documented cases of invertebrate SSB come from insects, spanning hundreds of species. That number reflects research focus more than biology, though. Ants belong to the order Hymenoptera, which turns out to be significantly underrepresented in the research literature relative to how many species exist. In other words, scientists haven’t looked very hard at ants specifically, so the true frequency of same-sex interactions is almost certainly higher than what’s been recorded.
When researchers do observe it, same-sex mounting between male ants or between workers is the most commonly noted behavior. These interactions can look identical to opposite-sex mating attempts, complete with the full sequence of mounting and genital contact.
Why It Happens: Not Just a Mistake
For decades, the dominant explanation was simple: insects can’t tell each other apart. This “mistaken identity” hypothesis suggested that males and workers sometimes mount same-sex partners because they misread chemical signals and accidentally target the wrong individual. It was a tidy explanation, and it let researchers move on without much further investigation.
Recent multispecies analyses have challenged that idea. A study published in the Proceedings of the National Academy of Sciences found that patterns of same-sex behavior in insects don’t line up well with the mistaken identity model. Instead, the data points toward something called the “tension reduction” hypothesis, which proposes that sexual behavior between same-sex individuals helps defuse aggression and social conflict. This explanation has long been studied in mammals and birds (bonobos are the classic example), but it appears to apply in insect colonies too.
This makes intuitive sense for ants. Colonies are high-density societies where thousands of individuals live in close quarters, compete for food, and navigate strict social hierarchies. Any behavior that reduces conflict could carry real survival value for the colony as a whole.
Ant Colonies Are Already All-Female Societies
One thing that makes ants unusual in this conversation is that the vast majority of ants you’ll ever see are female. Workers, soldiers, and foragers are all female. Males exist almost exclusively to mate with queens during brief mating flights, and they die shortly after. So the everyday social life of an ant colony is already an all-female affair, with females grooming, feeding, and physically interacting with other females constantly.
Some of these interactions blur the line between social behavior and sexual behavior. In certain species, workers have remarkable reproductive flexibility. When a queen dies or is removed, some workers can activate their ovaries and begin laying eggs. In the most extreme cases, workers called “gamergates” take over the queen’s reproductive role entirely. In species like the Indian jumping ant, these reproductive workers mate sexually and produce both male and female offspring. Dominance hierarchies among workers determine who gets to reproduce, with other workers actively policing any unauthorized egg-laying by attacking or intimidating the offender until her ovaries stay undeveloped.
These power struggles involve intense physical contact between females, including behaviors that overlap with mating rituals. Whether you’d call that “sexual” depends on how broadly you define the term.
Queens That Partner With Other Queens
Perhaps the closest thing to a same-sex partnership in ants is cooperative colony founding between queens. In many species, newly mated queens strike out alone to start a colony. But in species with polygyne tendencies (meaning colonies that tolerate multiple queens), unrelated queens actively seek each other out and found colonies together.
Research on fire ants and related species found that these cooperative queens are genuinely attracted to one another. They cluster together, share the labor of raising the first generation of workers, and maintain their partnership for months after workers emerge. In one experiment, 72% of cooperatively founded colonies still had at least one queen alive after five months. Colonies co-founded by cooperative queens were about five times more likely to still have both a brood and all founding queens alive compared to colonies started by queens that typically go it alone.
These aren’t sexual pairings in a reproductive sense. Both queens have already mated with males. But they are voluntary, long-term, same-sex partnerships between unrelated individuals who chose each other over solitude, and the arrangement gives their colonies a measurable survival advantage.
Why “Gay” Doesn’t Quite Fit
Sexual orientation, as humans experience it, involves identity, attraction, and consistent preference over time. An ant’s nervous system doesn’t support that kind of internal experience. Ants operate primarily through chemical signals, responding to pheromones and cuticular hydrocarbons that coat every individual’s exoskeleton. Their “decisions” about who to mount, groom, or cooperate with are driven by these chemical cues and by the immediate social context, not by stable individual preferences.
This is why entomologists use the clinical term “same-sex sexual behavior” rather than calling insects gay or homosexual. The field has moved away from anecdotal descriptions partly to avoid anthropomorphism, the tendency to project human experiences onto animals. Decades of bias against narrative accounts of animal behavior mean that unusual behaviors like SSB have likely been underreported, especially in less-studied groups like ants.
That said, the behavior is real, it’s common, and it appears to serve genuine biological functions rather than being a simple glitch in sex recognition. Ants engage in same-sex mounting, form same-sex cooperative bonds, and live in societies where female-female physical intimacy is the norm. Whether that counts as “gay” depends entirely on what you mean by the word. If you mean exclusive, lifelong attraction to the same sex as a core part of identity, then no. If you mean same-sex sexual and social behavior that occurs naturally and repeatedly across species, then ants have been doing it for millions of years.