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Spiders Don’t Have Ears, But They Can Eavesdrop Through Their Web

Orb spiders could eavesdrop on your conversations—even though they don’t have ears.

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You may know them as silk weavers, web architects, bug slayers, or maybe just miniature eight-legged monsters—such is the versatility of spiders. But despite this already impressive résumé, scientists have discovered what may be the arachnid’s most intriguing talent yet: hearing without ears.

in a paper published Tuesday in the Proceedings of the National Academy of SciencesBinghamton University researchers discovered that orb spiders (like those in Charlotte’s Web) can detect sounds through tiny vibrations in their spider web.

It’s a clever auditory outsourcing trick that the animals may be using to precisely balance their eardrums that prevent them from “hearing” like us.

As humans, we rely on our eardrums to convert sound wave pressure into signals our brain can understand. Once our brain processes these signals, we learn what the sound is, where it’s coming from, how loud it is, and so on. Without eardrums the world would stand still. Most other vertebrates also hear this way, but animals like insects and spiders do not have such a hearing aid.

Studies have proven that over the years hearing kind of spiders with the tiny hairs on their crawling legs because the fluff is sensitive to nearby sonic vibrations, but that’s about all experts thought arachnids’ sense of hearing was – until now, that is.

And while the results of the new grid vibration study are amazing in themselves, they also point to something even more stunning. Orb-weaving spiders could physically melody their spider web strings target whatever tone they desire.

The concept is similar to how we tune in to our car stereo to find our favorite station – except I would assume spiders are more interested in the hum of a bee, the flapping of a dragonfly’s wings… or maybe a human scream?

Either way, maybe it’s about time we added “Radio Engineer” to the intriguing Spider abilities.

The outsourced listening to orb-weaving spiders

For their new study, the researchers collected a bunch of orb spiders from windows on the Binghamton University campus where the experiments were being conducted.

They placed each creepy crawly in a rectangular frame in a soundproof room and waited for the spiders to build their web creations. The team then played sounds to see if the spiders would listen and respond – they did, even to sounds that were really (really) quiet.

Then, to take it a step further, the team tried playing the sounds from different angles to see if the spiders could figure out where it was coming from – they did, and with a loud bang 100% Accuracy.

In fact, after analyzing the orb-weaving spider webs, the researchers found that the delicate creations quickly captured movement of nearby air particles, which vibrated as a result of the sound waves. The team concluded that when orb-weaving spiders stand on the vibrating strings, they can sense, or rather “hear,” sounds.

The researchers also found that while hearing the sounds, the spiders either crouched down or stretched on the web. Although this behavior has been observed in the past, it was not due to many reasons. But with their new knowledge that cobwebs have something to do with the spiders’ auditory perception, the team began to connect the dots.

It’s likely, they say, that spiders actively alter the tension of the threads, such as by crouching, thus adjusting their web to tune in to specific sounds, such as a radio.

Before making any major claims, however, the researchers wanted to address one final major caveat. “The real question is, if the web moves like this, does the spider hear using it?” Ron Miles, mechanical engineer at Binghamton University and co-author of the study, said in a statement. “That’s a difficult question to answer.” To get around this, Miles and co-author Junpeng Lai, a graduate student in Miles’ lab, conducted a final experiment.

They used a mini-speaker to play sounds for the spiders, which almost completely faded in volume before they reached the web, but continued to propagate strongly as vibrations through the webs’ threads. Essentially, this isolated the string vibration aspect from the actual audible aspect of the sound. According to the study, four out of 12 spiders responded to even the extremely weak signal, meaning they could feel the vibrations in the web themselves and ruled out the reservation.

Going forward, Miles urges that future research should examine whether other species of spiders exhibit the same behavior, although he says “It’s reasonable to assume that a similar spider would respond in the same way on a similar web.”

And even further back, he believes these findings could influence the way we design microphones, hearing aids and cell phones. “The spider is really natural evidence that this is a viable way to capture sounds with viscous forces in the air on thin fibers,” Miles said.

“If it works in nature, maybe we should take a closer look.”

Spiders Don’t Have Ears, But They Can Eavesdrop Through Their Web Source link Spiders Don’t Have Ears, But They Can Eavesdrop Through Their Web

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