This is what we can learn from turtles and octopuses about a happy, solitary life

The solitary lifestyle may have great advantages in the animal world . Can we humans learn something from them?

The Middle Eastern blind mole rat is an introvert par excellence . It lives about 30 centimetres underground and digs its own tunnel system, where it remains for most of its life, collecting roots, tubers and bulbs.

Each mole rat has its own territory, for good reason: if one mole rat accidentally burrows into another's tunnel, the rodents will bare their teeth or bite each other in violent, often deadly battles.

Blind mole rats typically only interact with others of their species during mating season , but even at those rare times, they must proceed with caution. The male burrows through the ground toward a female, but stops before entering her tunnel. For several days, they send out vibrating signals by tapping their heads on the roof of the tunnel.

Only when the female expresses interest in meeting her does the male advance, mate with her and leave. After closing the tunnel behind him, he continues his solitary lifestyle .

Such solitary lifestyles are widespread across the animal kingdom . Even among mammals (a generally sociable group), 22% of species studied are largely solitary, meaning that males and females sleep and forage or hunt alone most of the time.

But solitary animals have received relatively little attention from scientists. Perhaps because we are social creatures, we are more drawn to studying creatures that cooperate in groups to protect themselves or to find food, reproduce and raise their young.

Experts say that for a long time, many scientists tended to overlook the solitary life , considering it a more primitive and basic state of existence, associated with antisocial behavior and low intelligence.

But researchers are beginning to recognize that some animals evolved to be solitary precisely because it can be highly beneficial to avoid the competition and stressful conditions of group living. Moreover, many solitary animals are in fact highly intelligent and live diverse and complex social lives, despite their loneliness.

Although blind mole rats are an exception, many solitary animals tolerate, learn from, and sometimes even cooperate with others of their kind, allowing them to enjoy the best of both worlds.

As humans spend more and more time alone, these animals remind us of the many benefits of solitude and that living alone is not the same as being lonely. “Perhaps by studying solitary species and how they achieve success with this tactic … we can also better identify for human society what is good about being alone,” says behavioral ecologist Carsten Schradin of the National Center for Scientific Research in Strasbourg, France, co-author of a 2024 study on solitary life in mammals.

Living in groups has many advantages . Consider zebras, which find safety in herds, and lions, which often hunt together to defeat prey larger and faster than themselves. Some birds help breed, and chimpanzees socialize by removing parasites from each other. But there are also disadvantages .

In a group, “every shelter has to be shared, every piece of food has to be shared, every access to a mate has to be shared,” says David Scheel, a behavioral ecologist at Alaska Pacific University. “Or if it can’t be shared, only one can get it.”

And while hunting together and sharing food makes sense for animals like lions, which are often surrounded by large, abundant prey that can feed several individuals, this is less beneficial in situations where prey is smaller and harder to share. It is also not as useful when prey is scattered across the landscape, where it is harder to find.

That’s probably why armadillos and anteaters hunt alone for a few insects far away, and why tigers, which roam far and wide to find relatively scarce prey, hunt alone—which helps them sneak up on their prey more easily. To further reduce competition, tigers and other solitary hunters stake out small hunting territories that they defend from other predators . For blind mole rats, solitude means not having to constantly compete for tunnel space, which requires a lot of energy to dig.

Solitary animals may also face less competition for mates and a lower risk of contracting diseases and parasites. Meanwhile, females raising their young can put all their energy into caring for their own offspring without having to tend to the offspring of their neighbors, as some more social species do. For other creatures, such as sloths, their camouflage may work only if they are not in large groups.

“If you live alone, you attract less attention,” says Lindelani Mayuka, a zoologist at the University of the Witwatersrand in Johannesburg, South Africa, and co-author of the study with Schradin.

Living alone poses other challenges , such as missing out on the benefit of huddling to stay warm. But some animals, such as the Karoo rat of southern Africa, overcome this problem by building large burrows to protect themselves from sudden temperature changes and predators, Mayuka says.

For highly social animals, being alone can be stressful (often leading to poor health and anxiety), but solitary animals cope just fine.

In fact, Middle Eastern blind mole rats become stressed and anxious when placed next to each other, even if there is a barrier between them, and the smaller, more submissive individuals suffer the most.

“They can die from the stress they are under,” says Tali Kimchi, a behavioral neuroscientist at the Weizmann Institute in Israel who studies blind mole rats in her lab.

Like all mammals, mother blind mole rats care for their babies, but they can become hostile and force their babies to dig far away from their tunnel. “It sounds funny, but that’s how these creatures survive,” she says.

Not all solitary species actively repel each other. Many are attracted to shared resources and have surprisingly rich social lives, tolerating each other and even cooperating when it makes sense.

For example, Karoo bush rats living near other related individuals have frequent and friendly interactions with each other: they share feeding areas with related females and sometimes even build burrows at the end of the breeding season when there is a high demand for burrows.

“Just because some animals live alone doesn’t mean they don’t have social interactions,” Mayuka says.

Even some octopuses (a group once considered so solitary that it was a joke that they only got together to mate or eat each other) sometimes group together, Scheel says.

At a site in Jervis Bay in eastern Australia, individuals of a species called the shadowy octopus are attracted to the availability of shelter.

This probably started when an octopus piled up discarded shells after eating and these eventually stabilized enough sediment for another octopus to build its burrow inside.

This new resident then created its own pile of discarded shells, until as many as 16 octopuses were gathered in one spot, says Scheel, who has been studying the site with colleagues.

In this “octopus city,” individuals find themselves in a much more crowded situation than they are used to and exhibit curious behaviors to deal with others of their species.

Males sometimes try to force females to stay nearby and chase other males, even crawling into other males' dens, wrestling them, and chasing them away.

Sometimes, when evicted males return to their den, “the male that evicted them may come back and repeat the eviction,” Scheel says. And as they clean their dens, octopuses often push debris over to their neighbors’ side.

Sometimes they hold onto debris and use their funnels to hurl it at each other, says Scheel, who documented some of these interactions in a 2022 paper.

Neither aggressive nor cooperative, some scientists call these behaviors “nudging,” says Scheel, who is still figuring out the purpose of these interactions.

“Here we’ve put a solitary animal in a complex social situation, and all they do is push each other around, and they seem to be completely healthy. That suggests that either they’re less solitary than we thought, or the stress of being [social] isn’t as severe [for them].”

These sophisticated social interactions underline the intelligence of solitary creatures.

Similarly, researchers have seen some solitary reptiles closely observing other individuals and using that information to solve problems, an ability previously thought to be exclusive to humans, says behavioral scientist Anna Wilkinson of the University of Lincoln in the United Kingdom.

“Animals that might not naturally form complex groups may actually have very sophisticated aspects of social learning,” he adds.

In experiments with red-footed tortoises, which forage for food on their own but can encounter each other under fruit trees, for example, Wilkinson presented them with a transparent V-shaped fence with food inside. Neither animal could reach the food until Wilkinson and his colleagues trained one of them to do so.

Seeing their reptile companion reach for the food, the other turtles immediately followed suit.

It is especially remarkable to see that reptiles have the ability to learn from other individuals through imitation, considering that many of them have evolved to hatch from eggs without a parent nearby to teach them skills.

Evidence like this leads scientists to view solitary living not as a fixed, uniform category but as a continuum: from animals like the (arguably) antisocial blind mole rat to species that live largely alone but learn and cooperate with each other.

Some species even combine solitary and more social lifestyles, such as the striped mice that live communally and become solitary once they start breeding, or the raccoon-like coatis, whose males are solitary and females hunt in groups.

Studying solitary animals and their social networks can help conservationists better protect and preserve their populations from human threats.

Mayuka and Schradin have already begun an effort to build a community of scientists to further decipher the lives, benefits, needs and challenges of solitary animals."

“Being solitary is not simple or primitive,” Schradin says. “It can be quite complex and present challenges… that are solved in different ways by different species.”

Understanding the full breadth of solitary life might even be helpful to individuals.

Kimchi is studying changes in the brains of blind mole rats as they move from an introverted stage to a more social one, during mating and while raising their young.

Perhaps this research can help scientists understand how people with neurological or psychiatric conditions become socially withdrawn, he explains.

But solitary animals can also help us consider that being alone doesn't necessarily have to be problematic, even though it has been somewhat stigmatized in our extrovert-driven society, Schradin says.

“Social” solitary animals build meaningful social networks around themselves, and people who live alone can and do so, too.

“Being alone,” Schradin says, “may also be the best option for many humans.”

*By Katarina Zimmer