Buzz
While many animal limbs have clear and straightforward functions, evolution sometimes leads to surprising uses for old parts, giving them exciting new roles.
10. Horses Use Their Ears and Eyes as Signals for Communication
Horses are more expressive than we realize. Beyond their vocalizations like neighs and brays, they also use their eyes and ears to communicate, with their ears serving as highly flexible signals, much like turn indicators on a car.
In an experiment, University of Sussex PhD student Jennifer Wathan and her advisor Karen McComb took photos of horses looking at food-filled buckets. They then manipulated some images to hide either the eyes or ears, scaling the pictures to real-life size before presenting them to actual horses who were given the option to choose between two similar food buckets.
When shown the unaltered images, the test horses usually selected the same bucket as the ones in the pictures. However, when either the eyes or ears were obscured, this behavior no longer occurred. The horses seemed to rely slightly more on the ears than the eyes for making their choice.
The research implies that horses use their ears for signaling either the location of food or the presence of danger, such as predators. We might have understood this sooner, but sometimes our human-centric views limit our understanding. Research on animal communication often focuses on gestures, body language, and vocalizations because these elements resemble components of our own communication.
9. Hippos Use Their Tails to Spread Feces
With its goofy expression, round body, and short, stubby tail, the hippopotamus is one of the animal kingdom's most unsuspecting killers. Despite their seemingly harmless appearance, hippos are among the deadliest creatures on Earth, luring victims into a sense of security with their chubby charm before striking with incredible speed and razor-sharp teeth.
However, not all aspects of these creatures are terrifying. Their tiny tails are not only comical in appearance but also in their function. Dominant male hippos mark their territory by scattering feces, but instead of walking around to do so, they spin their small tails like leathery propellers, flinging excrement into the air.
This is how they distribute their feces—sometimes mixed with a bit of urine for extra potency—randomly in all directions to keep rival males from invading their territory. Interestingly, juvenile hippos seem inexplicably attracted to these smelly piles and are often seen following older males, licking at their rear ends.
8. Trap-Jaw Ants Use Their Mandibles to Launch Themselves to Safety
Trap-jaw ants have mandibles that act like shears, snapping at a jaw-dropping 40 meters per second (90 mph). With such incredible speed and force, they can slice through enemies in the blink of an eye. Astonishingly, these formidable jaws are also used by the ants to defend themselves as well as to attack.
Researchers observed that the ants would sometimes launch themselves into the air using their exceptionally strong mandibles. The exact reason was unclear, but it was possibly an evasive tactic.
As usual, scientists sought to unravel this curious behavior by recreating it in the lab. They introduced antlions—larger insects that are known to feed on ants. To capture their prey, antlions dig pits in the sand that collapse beneath the ants’ feet, trapping them for a quick meal.
Indeed, when trap-jaw ants were at risk of falling into the sand, they used their mandibles to propel themselves to safety. Moreover, ants whose jaws were glued together were only half as likely to escape being eaten.
7. Sawfish Snouts Can Detect Electrical Fields
The sawfish is a feared predator of the aquatic world. Its large, jagged appendage serves as a terrifying weapon capable of slicing smaller fish clean in half. However, the sawfish's multi-functional muzzle also has the ability to detect electrical fields emitted by living organisms.
While examining several sawfish specimens that had died naturally, researchers discovered that the fish's fimbriated snouts were filled with tiny pores. These pores indicated the animal's electrical sensitivity, a feature shared by other creatures with similar abilities. These sensors are typically located around the mouth, allowing the sawfish to swiftly clamp down on anything that triggers its electro-location system.
It might seem unfair that evolution equipped a saw-faced predator with what essentially amounts to a video game mini-map, but it’s a crucial tool for survival in murky waters where visibility is reduced to mere millimeters when sediment is stirred up. By using its saw as an electrical rangefinder and guide, the sawfish remains a lethal hunter in places where others would be blind.
6. Ants Use Their Antennae to Grip Tunnel Walls
Not long ago, researchers conducted one of the most thorough studies on ant tunneling. It’s common to fill a transparent container or tube with dirt and observe the ants at work, but this time, X-ray tomography allowed the scientists to watch the ants in action under conditions that closely resembled their natural environment.
The researchers discovered that the tunnels were constructed with precise, optimal dimensions to ensure structural strength. To trigger a mini-collapse (to study how the ants would respond and rebuild), scientists used a small piston to shoot a puff of air into the tunnel. To their surprise, the displaced ants immediately latched onto the tunnel walls using their antennae, revealing a completely new use for this familiar appendage.
It turns out that the tunnels are not only designed for stability but are also small enough to allow the ants to grip the walls—an invaluable adaptation for these busy insects that frequently navigate vertical tunnels.
5. Some Owls Use Their Faces As Radar Dishes
Owls, often regarded as the wise overseers of the animal kingdom, are not just symbolically wise but also deadly predators. Beneath their sage-like appearance, these birds are equipped with evolutionary advantages that enable them to swiftly track and strike down any creature that catches their interest or anger.
A key feature in the owl's arsenal is its face. Unlike most animals with round, fluffy heads or pointy muzzles, owls have flat, elliptical faces. This design serves a vital function—they can use their faces as natural satellite dishes. The distinctive flat shape funnels sound waves directly to their ears, enhancing their ability to detect the faintest sounds.
The owl's ears are also quite unique because they are not positioned symmetrically. One ear sits higher than the other, giving the owl an even more refined auditory map of its surroundings. This allows them to naturally process the slight time difference between the sound waves reaching each ear. Thanks to this incredible adaptation, owls possess hearing that is ten times sharper than ours, enabling them to snatch unsuspecting rodents hiding beneath layers of snow.
4. Some Turtles’ Anuses Double As Respiratory Systems
White-throated snapping turtles, along with other turtle species, faced an evolutionary dilemma: They are turtles. Slow-moving and not particularly armed, these creatures prefer to evade danger by hiding underwater. Constantly resurfacing for air would make them easy targets, so they developed an ingenious solution. They breathe through their anuses.
Yes, you read that correctly. Unlike the single-purpose anuses of other animals, a turtle's rear end, called a cloaca, handles the evacuation of waste but also serves as a respiratory organ. This clever adaptation allows the turtles to stay submerged for days at a time. By drawing oxygen from the water that flows through their backside—essentially functioning like anal gills—they can remain hidden from predators.
Unfortunately, pollution caused by industrial processes has fouled the waters, causing the turtles’ unique breathing mechanism to suffer. Contaminated with sediment and chemicals, the polluted waters have hampered these creatures' ability to stay hidden, with fewer than 1 percent reaching adulthood due to the harsh conditions.
3. Moth Genitals Produce Ultrasound
In the animal kingdom, genitals typically serve a singular, straightforward function, but some moths have evolved a fascinating, multipurpose tool. These moths use their genitalia as sonic jammers, emitting ultrasonic sounds to confuse and thwart bats.
Tom and Jerry would have been more accurately portrayed as bat and moth; the two species have been engaged in an ongoing evolutionary battle for survival. To stay alive, each has had to develop new strategies for either hunting or escaping. Thanks to the magic of evolution, these adaptations come in all forms.
For example, sonar-jamming penises emerged around 26 million years ago. Though moths may appear smaller and less intimidating than bats, they are far from defenseless. Armed with thorny barbs on their legs and impressive flying abilities, moths have found a unique way to avoid their predators. By rubbing their penises against their abdomens, they generate ultrasonic pulses, similar to the echolocation sounds that bats use to locate prey.
2. Golden-Winged Warbler Ears Can Detect Tornadoes
With their signature yellow-tinted patches and a weight of only 9 grams (0.3 oz), golden-winged warblers are small but mighty. These tiny birds embark on grueling seasonal migrations that span approximately 5,000 kilometers (3,000 miles).
In 2014, scientists uncovered a remarkable ability in golden-winged warblers: they can predict tornadoes. The discovery began when five geotagged warblers unexpectedly veered off course, taking a 650-kilometer (400 mi) detour to Mexico several days after completing their migration. At first, it wasn’t clear why these birds left early. The next day, tornadoes ravaged the area. It seems that the warblers’ ears are finely attuned to detect low-frequency sounds, like the rumble of a tornado, allowing them to sense the disaster days and hundreds of kilometers before it strikes.
This breakthrough was a result of serendipitous science. The warbler study wasn’t designed to investigate tornado prediction, but rather to determine if the delicate birds could be efficiently tracked using geolocators.
1. Bat Wings Are Full Of Sophisticated Wind Sensors
Bats perform jaw-dropping aerial maneuvers to catch their prey, and scientists are eager to learn from them to create better aircraft. As the only mammals capable of self-powered flight, bats offer a unique source of technological inspiration, differing from birds and flying insects. However, based on recent research, we may not see bat-winged planes any time soon.
Bat wings are truly astonishing. Researchers observed the activity of sensory neurons in bats as gusts of air were directed at the numerous tiny hairs on their wings, revealing a remarkably intricate connection between the wings and the brain. To execute their incredible aerial feats, bats essentially 'feel' the air, using these hairs as a sensory apparatus that provides immediate and precise feedback on airflow changes.
This extraordinary tactile sensitivity makes the bat wing an unmatched aerodynamic marvel—far superior to anything we’ve developed. The multipurpose wing functions as a propeller, flipper, airplane wing, airfoil, and more, as explained by Cynthia F. Moss, a neuroscientist at Johns Hopkins University.
