As the Earth gets hotter, humans aren’t the only ones worrying about staying cool.
From the 100-degree summers of sub-Saharan Africa to the sticky humidity of South Florida, animals have learned to live in the most extreme heat. They have evolved cooling methods that effectively rival air conditioners. Except, they don’t consume enormous sums of energy.
In the evolutionary Olympics, humans are at an inherent disadvantage when it comes to regulating temperature. Homo sapiens have been around for about 750,000 years, air conditioning for a mere century of that time. Insects, by comparison, have had hundreds of millions of years to perfect the art of cooling.
Some animals dig deep underground burrows that measure several degrees colder than the surface. Others build chimneys, allowing hot air to rise while keeping cool air trapped.
Here are five animals whose natural air conditioning could teach us something about cooling.
Fiddler crab
Fiddler crabs, native to most of the U.S. coastline and prolific in Florida, are best known for the males’ distinctive, oversized claw, about the same length as their inch-wide bodies.
Legend has it that early English settlers saw the crabs eating – that is, moving their small claw diagonally across their big claw and into their mouths – and likened the motion to a musician guiding a bow across a fiddle.
Fiddler crabs live in small holes, or burrows, in the sand. If temperatures get too hot – as climate scientists expect them to become in the coming years – the crabs can retreat into their burrows, which tend to be about 5 degrees Celsius, or 41 degrees Fahrenheit, cooler than outside, said Zachary Lane, a postdoctoral associate at the University of Florida’s Whitney Lab for Marine Bioscience.
Fiddler crabs play a crucial role in their ecosystems. By digging burrows, they create underground tunnels filled with oxygen, a process known as aerating the soil. That oxygen feeds wetland plants, like grasses – and it keeps the crabs cool.
“You can imagine that their burrows are, in a sense, air conditioned,” Lane said.
But as human-induced climate change warms oceans, the tropics-loving fiddler crabs are moving further toward the poles than ever before. Most recently, researchers spotted them as far north as Maine and south as Argentina.
Though the crab’s range is expanding, its limit is dictated by how much cold it can tolerate. There’s no such thing as “too hot” for the fiddler crab, Lane said. The crab is unlikely to be pushed out of areas near the equator, thanks to strategies it developed to mitigate heat.
Gopher tortoise
Underneath the ground across the southeastern United States lie extensive networks of tunnels brimming with snakes and other wildlife.
The owners of those tunnels? Gopher tortoises.
The tortoises build and live in sandy, 15-foot-long underground passages, known as burrows. Inside, they enjoy a relatively cool life, with their burrows trending about 11 degrees Celsius, or 50 degrees Fahrenheit, cooler than the surface.
That's why gopher tortoise burrows could become “critical thermal refuge sites” for both their owners and other native animals, like rattlesnakes, frogs and spiders, according to a 2023 study.
Burrowing is like building a tent – both methods shield against sunlight, said Martin Main, a UF ecologist.
Thanks to their burrows, rising temperatures aren’t a direct threat to gopher tortoises. The bigger concern, Main said, is habitat loss from land development and urbanization.
“Animals that require certain kinds of forests or prairies or things like that, as they change, those animals will suffer,” Main said.
Florida classifies the tortoise as “threatened,” meaning it’s likely to become endangered in the near future. Under Florida law, it’s illegal to kill gopher tortoises or destroy their eggs or burrows.
“It's considered what they call a keystone species,” Main said. “All the other animals really depend on the gopher tortoise, primarily for its burrow.”
Termites
The Eastgate Centre in the capital of Zimbabwe is a termite building – and no, it’s not infested.
The center takes inspiration from sophisticated ventilation systems in termite mounds to cool its interior. The building’s architect, Mick Pearce, replaced air conditioning with a passive cooling system that stores heat during the day and releases it at night.
Some termite species, including those most common in Florida, are known for eating through buildings. But the vast majority of termites in the world spend time protecting their queens, tending to the colony and building mounds that can reach three stories high using mud and saliva.
The Eastgate Centre is the most famous example of termite cooling translating to the human world. The insects are popular choices for biomimicry, or imitating nature in human processes, said Arnold van Huis, an entomologist at Wageningen University in the Netherlands.
“Insects are extremely sophisticated,” he said, “and that has to do with the evolution of hundreds of millions of years.”
Van Huis studies insects as food and once visited The Eastgate Centre during his travels. While doing research in Kenya, he found termites hard to study, mostly because they spend most of their time underground.
Termites are “amazing animals,” Van Huis said, and added they were “extremely delicious.”
Some studies show that insects are highly vulnerable to extreme temperatures. Van Huis noted several insect species could die off if regular temperatures cross a threshold of 45 degrees Celsius, or 113 degrees Fahrenheit, according to studies.
But as the Earth gets warmer, Van Huis worries more about human resilience than termites.
“Insects are extremely efficient in adapting themselves,” he said.
Giraffe
Sara Ferguson learned firsthand that if you straddle a giraffe’s neck, you’ll be coated in its sweat and oil.
“You get a bit gross when you sit on a giraffe,” she said, laughing from her home in Namibia.
As a veterinarian with the Giraffe Conservation Foundation, Ferguson captures, tags and studies giraffes – a labor often involving high-adrenaline chases to ensure the animals don’t die of lethal overdoses of tranquilizer.
In the dry heat of sub-Saharan African, the giraffes’ long necks peek over the occasional desert tree. Their signature dark patches crackle on their fur like shards of glass, acting as hubs for absorbing and releasing heat. Researchers affectionately call the spots “thermal windows.”
Thermal windows could become an architectural reality, Ferguson suggested. Just like they do for giraffes, such windows would “make a building sweat through some areas and not others,” she said.
Giraffes are masters of minimizing resource use. They collect most of their water from eating dewy leaves, Ferguson said, and rarely drink water if it’s not readily available. Their thin, angular bodies leave little surface area for sunlight to hit. Their wide nose cavities circulate cool air when they breath, effectively air conditioning their brains.
Though she’s not an architect, Ferguson said, buildings could similarly become thin and tall to curb exposure to direct sunlight.
Giraffes are an iconic symbol of the African continent, Ferguson said, and they’re becoming increasingly rare.
Experts estimate there are just over 110,000 giraffes left on Earth – about a quarter of the number of elephants. In November, the U.S. Fish and Wildlife Service proposed listing three types of giraffes as an endangered species in hopes of “ensuring the United States does not contribute further to their decline.” Giraffe numbers are dwindling, the service writes, largely because of human population growth, habitat loss and other consequences of climate change.
Beaver
In North America, beavers are both a treasure and a nuisance.
The semiaquatic rodents are practiced architects. Their wood-and-mud dams prevent water from flowing, creating wetlands. Those wetlands tend to provide a cooler habitat for nearby wildlife – making beavers busy air conditioners.
Katharine Yagi, a professor at Brock University in Ontario, Canada, studied the effects of beavers on nearby endangered spotted turtles. In the study, she found the turtles thrived in the cool and regulated temperatures where beavers had dammed.
“It takes water a longer time to heat up,” Yagi said, “so it just absorbs that heat and puts the energy into growing things. There's going to be a lot of growth, lots of cover and shaded areas that help cool.”
Beavers can also be destructive.
In 2022, rushing water from a broken beaver dam swept away part of a highway in British Columbia. Flooding in residential areas can interfere with septic tanks and ground water.
Beavers and land developers often vie for the same space, causing some North Americans to resent the animals. It’s legal in Ontario to trap and kill beavers “as a last resort,” though the government encourages residents to first try other methods like planting repellant trees or installing wire fences.
Aside from acting as natural air conditioners, beavers and their dams play a critical role in the ecosystem – another keystone species. A loss of beavers could drain wetlands and force out other animals, Yagi said. It could also invite invasive species to overtake the changing habitat.
“Not having them would be a big problem,” Yagi said.
