Plants may not have ears, but they’re able to detect sound vibrations in ways that would astonish most gardeners. Scientific research has revealed some plants perceive and respond to acoustic signals in their environment. They then use those vibrations to make crucial decisions about defense, growth, and even reproduction.

In 2019, biologist Lilach Hadany of Tel Aviv University discovered evening primroses can pick up the specific frequencies of bees’ wings. Within minutes, the plants increase their nectar’s sugar concentration, making themselves more attractive to the visiting pollinators. Hadany surmised that the flower’s bowl-shaped blossoms act as an earlike structure, helping to detect the vibrations.

One of the world’s largest carnivorous plants is big enough to eat rats.

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Nepenthes rajah, the world’s largest pitcher plant, secretes a sweet-scented nectar to lure prey — including rats, frogs, and insects — into its acidic pitcher traps, which then slowly digest the unfortunate creatures.

And in 2014, researchers at the University of Missouri found that when a caterpillar chews on the leaves of a plant, it creates distinctive vibrations that travel through the plant’s tissues. Some plants can detect those very specific vibrations and perceive them as a threat; they then engage their chemical defenses, producing compounds that make their leaves less palatable to the munching insects. 

Researchers refer to this as “hearing” because the plants aren’t just reacting to being touched or shaken — they’re “listening” for the unique “sounds” (vibrational rhythms) of the specific input (such as a predator chewing). Remarkably, the study showed plants can distinguish between different vibrations, whether it’s a munching insect or another mechanical disturbance such as the wind or raindrops — activating their defenses only when genuinely threatened.

Further studies have shown plants can even use sound to navigate their environment. In 2014, researchers discovered that plant roots are capable of locating water sources by sensing the vibrations generated by moving water — further evidence that plants can sense more than we give them credit for.

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Hummingbirds sometimes seem otherworldly compared to other feathered friends. They see more colors than the human eye does and can even enter a deathlike state to survive frigid winter nights. But their most remarkable ability has to do with their incredibly fast-moving wings, with the fastest flapping upwards of 70 times per second. Thanks to those incredible appendages, hummingbirds can hover — and they’re the only species of bird that can do so on their own for a sustained period of time. Hummingbirds can also move up, down, left, right, forward, and yes, even backward (another unique ability), reaching speeds of 75 miles per hour. According to Audubon, the hummingbird also has really sensitive “brakes” and can switch from flying 25 miles per hour to coming to a dead stop within the length of a human index finger. 

A species of hummingbird is the smallest bird in the world.

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The world’s smallest bird is the bee hummingbird (Mellisuga helenae), which can be found only in Cuba. This pint-sized hummingbird is only 2.25 inches long and weighs around 2 grams — about the weight of a dime.

How are hummingbirds such aerial aces? Well, most birds achieve lift only when flapping their wings down, but hummingbirds swish their wings in a side-to-side, figure-eight pattern, which is more characteristic of an insect than a bird. (The feat has earned them the excellent nickname “hummingbugs.”) Although hummingbirds have evolved to use their wing muscles efficiently, their tiny bodies have an incredibly high metabolism, which means the creatures must constantly hunt for food to survive. Remarkably, hummingbirds can drain up to 10 drops of nectar from a flower in 15 milliseconds (or one-hundredth of a second).

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Within 12 hours of their birth, oysters begin pulling calcium out of the water to create their signature shells. For the first few weeks of their lives, these newborn bivalves zoom around in a current until they eventually settle on some hard substrate, whether it’s a rock, pier, or another oyster. This place of protection is where the oysters will spend the rest of their lives (which can be as long as 20 years). Eventually, usually a year after birth, it’ll be time for the oysters to breed, and that’s where things get interesting. 

Only oysters can make pearls.

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When debris gets caught inside an oyster so it can’t be flushed out, some species encase the unwanted irritant in a material called nacre, also known as mother-of-pearl. Although oysters make pearls, most commercial pearls come from saltwater clams or freshwater mussels.

Although born male, oysters have the impressive ability to switch their sex, seemingly at will. Every season, females can release up to 100 million eggs, and the amount of sperm released is so high it’s essentially incalculable. Once the egg and sperm are released, the oysters rely on pure chance for fertilization to take place, as the egg and sperm meet in the open water. Because any resulting larvae are extremely vulnerable to predators (especially filter feeders), oysters have evolutionarily compensated by being one of the most virile and sexually flexible species in the world — meaning that their ability to change sex likely evolved as a matter of survival. This impressive fecundity means that natural oyster reefs can grow to tremendous size; as little as 10 square feet of reef can house up to 500 oysters. Scientists theorize that water temperature could play a role in triggering whatever causes an oyster to change its sex, but many aspects of the process remain a mystery. 

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Watching an old Western might leave you with the perception that tumbleweeds have always been a part of America’s western landscape. However, many of the spiky bushes are actually an invasive species from Russia. Salsola tragus goes by a variety of names — including “Russian thistle” and “wind witch” — but its best-known title comes from the way the plant breaks free from the ground at the end of its growing season, blowing around and spreading hundreds of thousands of seeds. While some native tumbleweeds do exist — like Amaranthus albus, aka common tumbleweed — Russian thistle is highly invasive, a term scientists use to describe species that choke out native plants and cause ecological harm by altering habitats. Today, Russian thistle is the most common type of tumbleweed in California.

Tumbleweed plants can survive radioactive hot spots.

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They even thrive. In the 1950s, the U.S. government performed nuclear tests in Nevada’s deserts, noting that Russian thistle bushes were among the first plants to return to test sites. Despite being technically radioactive, tumbleweeds grew vigorously around the test sites.

Botanists believe Russian thistle first put down roots in South Dakota around 1873, accidentally mixed into containers of flaxseed brought with European immigrants and growing unchecked in arid, desolate regions because it requires minimal water. Russian thistle gained such a stronghold in Western states that it alarmed government botanists, who reported in the 1890s that the plant had claimed as much as 35,000 square miles of land in just two decades of growth. While wind helped disperse the seeds, the early days of the railroad system also spread seeds inside batches of contaminated agricultural material, both throughout the U.S. and as far north as Canada.

Tumbleweeds may seem relatively benign to humans, but they are known to gather en masse during windstorms, causing highways to shut down and even trapping people in their homes and cars. Newer species are capable of reaching 6 feet tall, prompting naturalists to remove them wherever they crop up with the help of shovels and herbicides.

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