No Venom, No Problem: This Spider Uses a Slingshot to Catch Prey

Courtesy of Sarah Han
Courtesy of Sarah Han

There are thousands of ways nature can kill, and spider species often come up with the most creative methods of execution. Hyptiotes cavatus, otherwise known as the triangle weaver spider, is one such example. Lacking venom, the spider manages to weaponize its silk, using it to hurl itself forward like a terrifying slingshot to trap its prey.

This unusual method was studied up close for a recent paper published in the Proceedings of the National Academy of Sciences by researchers at the University of Akron in Ohio. They say it's the only known instance of an animal using an external device—its web—for power amplification.

Hyptiotes cavatus's technique is simple. After constructing a web, the spider takes one of the main strands and breaks it in half, pulling it taut by moving backwards. Then, it anchors itself to a spot with more webbing in the rear. When the spider releases that webbing, it surges forward, propelled by the sudden release of stored energy. In the slingshot analogy, the webbing is the strap and the spider is the projectile.

This jerking motion causes the web to oscillate, tangling the spider's prey further in silk. The spider can repeat this until the web has completely immobilized its prey, a low-risk entrapment that doesn’t require the spider to get too close and risk injury from larger victims.

The triangle weaver spider doesn’t have venom, and it needs to be proactive in attacking and stifling prey. Once a potential meal lands in its web, it’s able to clear distances much more quickly using this slingshot technique than if it crawled over. In the lab, scientists clocked the spider’s acceleration at 2535 feet per second squared.

Spiders are notoriously nimble and devious. Cebrennus rechenbergi, or the flic-flac spider, can do cartwheels to spin out of danger; Myrmarachne resemble ants and even wiggle their front legs like ant antennae. It helps them avoid predators, but if they see a meal, they’ll drop the act and pounce. With H. cavatus, it now appears they’re learning to use tools, too.

[h/t Live Science]

Beyond Tiger King: 10 Fascinating Animal Documentaries You Can Stream Right Now

A scene from Catwalk: Tales from the Cat Show Circuit (2018).
A scene from Catwalk: Tales from the Cat Show Circuit (2018).
Markham Street Films

By now, you've probably already binged Netflix's bewilderingly bonkers docuseries Tiger King (2020). If you're ready to dive deeper into the animal kingdom, there are plenty more documentaries out there. From wildcats to whales, these 10 films will take you on a cinematic adventure around the world, introducing you to captivating creatures and the people who love them.

1. The Tigers of Scotland (2017)

The Tigers of Scotland (2017) brings viewers as up close and personal as possible with a small but mighty feline: the Scottish wildcat. The film delves into the efforts to conserve the disappearing Highland tiger, as well as the history and mythology surrounding the UK’s only “big cat.”

Watch it: Netflix, Amazon, iTunes

2. Ghost of The Mountains (2017)

This 2017 Disneynature documentary will transport you to the world’s highest plateau in search of a family of snow leopards. These cats are famously tough to find, so Ghost of the Mountains offers viewers behind-the-scenes footage of what it’s like to track the elusive beasts.

Watch it: Netflix, Google Play, Youtube

3. Catwalk: Tales from the Cat Show Circuit (2018)

This delightful documentary takes you deep into the competitive cat show circuit. Both charming and at times cutthroat, the film brings viewers on a journey to see which of the many cool cats and kittens will be crowned Canada's top cat.

Watch it: Netflix

4. Kingdom of the White Wolf (2019)

Follow along as a National Geographic explorer and photographer embeds with a white wolf pack in the high Arctic. These wild wolves aren't used to seeing people, giving the filmmakers—and audience—an intimate window into the pack's daily lives and familial bonds. In addition to showcasing captivating footage of the animals, the three-part docuseries also features sweeping views of the starkly beautiful Ellesmere Island.

Watch it: Disney+, YouTube TV

5. Dogs (2018)

This docuseries, which highlights various dogs and their humans from around the world, celebrates the bond between people and their pups. But it’s more than just a montage of feel-good moments about humankind’s best friend: Each episode tells a broader tale about the human condition, crafting an emotional narrative that pulls at the heartstrings like a puppy tugging on a toy.

Watch it: Netflix

6. Dancing with the Birds (2019)

These birds will put your dad moves to shame. Watch the male avian performers shimmy, shake, and flash their feathers while attempting to woo their female mates. The documentary, narrated by Stephen Fry, offers a colorful look at the wonderfully wacky world of bird mating rituals.

Watch it: Netflix

7. Honeyland (2019)

This documentary follows Hatidze Muratova, one of the last wild beekeepers in a remote village in North Macedonia. She lives with her ailing mother, nurturing a traditional way of beekeeping passed down through the generations and striking a balance between making a living and maintaining ecological balance. But everything changes when a nomadic family settles nearby, threatening Muratova’s way of life. The resulting story is both sweet and stinging.

Watch it: Hulu, Amazon Prime, YouTube, Google Play

8. Virunga (2014)

This 2014 documentary highlights the park rangers fighting to protect the Congo’s Virunga National Park, home to the critically endangered mountain gorilla. As poaching and oil exploration threaten the park, the rangers and conservationists risk their lives to guard the rare creatures that inhabit it.

Watch it: Netflix

9. Harry & Snowman (2016)

In the 1950s, Harry deLayer bought Snowman, a run-down plow horse destined for slaughter, for just $80 at an auction. Within months, the two were taking the show jumping circuit by storm, launching both horse and rider to new heights. This documentary tells the story of the friendship the two developed, and chronicles their lives both in and out of the competitive spotlight.

Watch it: Amazon Prime

10. The Whale and the Raven (2019)

The waters around Canada’s Great Bear Rainforest are a haven for whales, who feed and find refuge in the quiet channels. With stunning visuals, this documentary highlights the tension of a community’s push to protect its wild places against the pressures of the ever-encroaching natural gas industry.

Watch it: Amazon Prime

Why Cats Like to Shove Their Butts in Your Face, According to an Animal Behavior Expert

This cat might be happier showing off its butt.
This cat might be happier showing off its butt.
Okssi68/iStock via Getty Images

Cats are full of eccentric behaviors. They hate getting wet. Their tongues sometimes get stuck midway out of their mouths, known as a “blep.” And they’re really happy hanging out in bodegas.

Some of these traits can be explained while others are more mysterious. Case in point: when they stick their rear end in your face for no apparent reason.

Are cats doing this just to humiliate their hapless caregivers? What would possess a cat to greet a person with its butt? Why subject the person who gives you food and shelter to such degradation?

To find out, Inverse spoke with Mikel Delgado, a postdoctoral fellow at the School of Veterinary Medicine at UC Davis. According to Delgado, cats don’t necessarily perceive their rectal flaunting as anything aggressive or domineering. In fact, it might be a cat’s way of saying hello.

“For cats, it’s normal for them to sniff each other’s butts as a way to say hello or confirm another cat’s identity,” Delgado said. “It’s hard for us to relate to, but for them, smell is much more important to cats and how they recognize each other than vision is. So cats may be ‘inviting’ us to check them out, or just giving us a friendly hello.”

For a cat, presenting or inspecting a butt is a kind of fingerprint scan. It’s a biological measure of security.

Other experts agree with this assessment, explaining that cats use their rear end to express friendliness or affection. Raising their tail so you can take a whiff is a sign of trust. If they keep their tail down, it’s possible they might be feeling a little shy.

If you think this situation is eased by the fact you rarely hear cats fart, we have bad news. They do. Because they don’t often gulp air while eating, they just don’t have enough air in their digestive tract to make an audible noise. Rest assured that, statistically speaking, there will be times a cat giving you a friendly greeting is also stealthily farting in your face.

[h/t Inverse]

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