8 Ways Spiders Are Creepily Clever

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iStock

You may already know that spiders can spin intricate webs and poison their prey. But that doesn't even begin to cover the all the sneaky abilities spiders have adapted to become the most fearsome organisms on eight legs. Here are some of the tricks spiders use to catch their meals while avoiding becoming dinner themselves.

1. THEY HAVE SUPER-POWERED SENSES.

Spidey-senses weren't just invented for comic books. Jumping spiders in real life have sharp eyesight and excellent hearing to make up for their inability to spin webs. Scientists long assumed that spiders couldn't hear because they don't have ears. But as researchers reported in a 2016 study, jumping spiders can "hear" perfectly fine—they just use the super sensitive hairs on their legs to do so. These same spiders can also see surprisingly well, as astronomer Jamie Lomax demonstrated when she used laser pointers to lure them away from her desk like they were tiny cats.

2. THEY MIMIC ANTS.

The fact that the jumping spider species Myrmarachne formicaria tricks predators into thinking it's an ant by mimicking its appearance isn't a new discovery. But exactly how it achieves this was unclear until recently. According to a Harvard study published in the Proceedings of the Royal Society B, the spider pulls off this deceptive stunt while using all eight legs to walk. During its performance, it takes 100-millisecond pauses to lift its front two limbs to its head so they resemble antennae. The switch is so fast that to a human looking from above, the spider appears to simply be walking with its back six legs while lifting its front legs off the ground. Scientists had to use high-speed cameras to prove this wasn't the case. 

3. THEY TUNE THEIR WEBS.

Despite lacking ears, spiders have some impressive musical talents. They treat the strands of their webs like the strings of a guitar, tuning them just right so they can detect certain vibrations. For their study published in the Journal of the Royal Society Interface, researchers from the University of Oxford and Charles III University of Madrid observed garden cross spiders maintaining their webs. They learned that adjusting the tension and stiffness of the silk allows the spiders to sense frequencies they can recognize. One signal might mean that prey is near, while another could be connected to structural issues with the web.

4. THEY PRETEND TO BE BIRD POOP.

Spider disguised as bird poop.

Min-Hui Liu et. al, Scientific Reports // CC BY-NC-ND 3.0

Camouflage is not unique among arachnids, but orb weaver spiders may win the prize for the most memorable disguise. In its juvenile stage of life, the spider will surround itself with a thick, white material in the center of its web. Its whitish abdomen blends into the "decoration," making the spider appear as if it's buried in a splatter of bird droppings. The unappetizing look is usually enough to convince predators to look elsewhere for a meal that's easier to stomach.

5. THEY CAST NETS.

Spider with web between it's legs.

Chen-Pan Liao, Wikimedia Commons // CC BY-SA 3.0

Bigger isn't always better when it comes to webs. Take the net-casting spider: The silken trap it uses to snare food is small enough to fit between its limbs. The spider poops out a pale "target" onto the forest floor and then hangs above it waiting, sometimes for hours, for an insect to come along and trigger a "trip wire" connected to the ground. Once that moment comes, it wastes no time lunging at its prey and enveloping it in its web. It then bites and paralyzes its prey before commencing the feast.

6. THEY CAN FIRE THEIR HAIRS LIKE TINY BARBED SPEARS.

If all else fails, at least tarantulas have their spear-like hairs to fall back on. A tarantula deploys its "urticating hairs" when it feels threatened. By grinding its back legs against its abdomen, it's able to shoot the barbed hairs at its target like a shower of tiny throwing stars. You don't have to be a predator to trigger this defense mechanism, as many tarantula pet owners have found out the hard way.

7. THEY SOMERSAULT.

When most spiders need to escape a dangerous situation, they rely on their eight limbs to scurry them to safety. The golden wheel spider curls up its body and rolls down hills to make an even speedier getaway. This type of spider is native to the Namib Desert in southern Africa, where steep, sandy dunes are abundant. When it's tucked into a ball, the spider can reach tumbling speeds of 3.2 feet per second.

8. THEY CREATE BUBBLE SUBMARINES AND SCUBA SUITS.

Even without gills, spiders have adapted some pretty clever ways of surviving underwater for long amounts of time. The diving bell spider weaves web balloons that extract dissolved oxygen from the water around it while filtering out carbon dioxide. Using this improvised scuba suit, the spider can last a whole day before it needs to come up for air. Then there are wolf spiders, which use a much more dramatic survival tactic. A 2009 study found that marsh-dwelling varieties of wolf spiders appear to drown after being submerged for extended periods. But once they're placed on dry land, they twitch back to life. Slipping into a coma underwater is how they're able to evade death.

A Simple Skin Swab Could Soon Identify People at Risk for Parkinson's

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iStock.com/stevanovicigor

More than 200 years have passed since physician James Parkinson first identified the degenerative neurological disorder that bears his name. Over five million people worldwide suffer from Parkinson’s disease, a neurological condition characterized by muscle tremors and other symptoms. Diagnosis is based on those symptoms rather than blood tests, brain imaging, or any other laboratory evidence.

Now, science may be close to a simple and non-invasive method for diagnosing the disease based on a waxy substance called sebum, which people secrete through their skin. And it’s thanks to a woman with the unique ability to sniff out differences in the sebum of those with Parkinson's—years before a diagnosis can be made.

The Guardian describes how researchers at the University of Manchester partnered with a nurse named Joy Milne, a "super smeller" who can detect a unique odor emanating from Parkinson's patients that is unnoticeable to most people. Working with Tilo Kunath, a neurobiologist at Edinburgh University, Milne and the researchers pinpointed the strongest odor coming from the patients' upper backs, where sebum-emitting pores are concentrated.

For a new study in the journal ACS Central Science, the researchers analyzed skin swabs from 64 Parkinson's and non-Parkinson's subjects and found that three substances—eicosane, hippuric acid, and octadecanal—were present in higher concentrations in the Parkinson’s patients. One substance, perillic aldehyde, was lower. Milne confirmed that these swabs bore the distinct, musky odor associated with Parkinson’s patients.

Researchers also found no difference between patients who took drugs to control symptoms and those who did not, meaning that drug metabolites had no influence on the odor or compounds.

The next step will be to swab a a much larger cohort of Parkinson’s patients and healthy volunteers to see if the results are consistent and reliable. If these compounds are able to accurately identify Parkinson’s, researchers are optimistic that it could lead to earlier diagnosis and more effective interventions.

[h/t The Guardian]

World’s Oldest Stored Sperm Has Produced Some Healthy Baby Sheep

A stock photo of a lamb
A stock photo of a lamb
iStock.com/ananaline

It’s not every day that you stumble across a 50-year-old batch of frozen sheep sperm. So when Australian researchers rediscovered a wriggly little time capsule that had been left behind by an earlier researcher, they did the obvious: they tried to create some lambs. As Smithsonian reports, they pulled it off, too.

The semen, which came from several prize rams, had been frozen in 1968 by Dr. Steve Salamon, a sheep researcher from the University of Sydney. After bringing the sample out of storage, researchers thawed it out and conducted a few lab tests. They determined that its viability and DNA integrity were still intact, so they decided to put it to the ultimate test: Would it get a sheep pregnant? The sperm was artificially inseminated into 56 Merino ewes, and lo and behold, 34 of them became pregnant and gave birth to healthy lambs.

Of course, this experiment wasn’t just for fun. They wanted to test whether decades-old sperm—frozen in liquid nitrogen at -320°F—would still be viable for breeding purposes. Remarkably, the older sperm had a slightly higher pregnancy rate (61 percent) than sheep sperm that had been frozen for 12 months and used to impregnate ewes in a different experiment (in that case, the success rate was 59 percent).

“We believe this is the oldest viable stored semen of any species in the world and definitely the oldest sperm used to produce offspring,” researcher Dr. Jessica Rickard said in a statement.

Researchers say this experiment also lets them assess the genetic progress of selective breeding over the last five decades. “In that time, we’ve been trying to make better, more productive sheep [for the wool industry],” associate professor Simon de Graaf said. “This gives us a resource to benchmark and compare.”

[h/t Smithsonian]

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