Buzz
Some researchers are truly passionate about spiders. This is why they spend decades observing the same arachnid and why the world recently witnessed the emergence of the first-ever trained spider. This love for spiders has led to many discoveries, yet countless mysteries remain to be solved.
Spiders are full of enigmatic traits, far more than just their eight legs. From baffling fossilization processes and producing milk richer than cow's milk, to weaving silk laced with graphene, these creatures continue to astonish scientists. And then there's the case of the spider who received death threats, prompting the police to intervene.
10. They Consume More Than Humans
Humans annually consume an average of 400 million metric tons of fish and meat. Occasionally, whales surpass this with a yearly intake of up to 500 million metric tons. However, in 2017, scientists calculated the total weight of spider prey, and the results were staggering. These tiny predators out-eat both humans and whales, consuming up to 800 million metric tons each year.
In order to determine this number, the team first had to estimate the biomass of the global spider population. They found that the Earth hosts 25 million metric tons of spiders. After calculating the food requirements for each unit of body weight, the total consumption was estimated to fall between 400 and 800 million metric tons.
Given that 95 percent of their diet consists of insects, the study demonstrated the significant role spiders play in nature. They help control insect populations, including those that are considered pests. The abundance of insects supports a flourishing spider population, which in turn serves as a food source for animals that prey on arachnids.
9. Spider Bondage
Unlike most other spiders, the nursery web spider (Pisaurina mira) doesn’t use its silk to trap prey. True to its name, the females spin webs to create nests, while the males use their silk for an entirely different purpose: to restrain the females during mating. No other spider species uses webbing in this way. This seemingly kinky behavior has been proven in lab settings to be an intelligent survival tactic.
In 2016, researchers divided male nursery web spiders into two groups. One group retained their ability to spin, while the other had it blocked. The females were introduced to the experiment. After mating, all the males who couldn’t spin were dead. However, those who managed to bind their mates survived. It turns out that once fertilization occurs, the female's instinct shifts to feeding on her mate for the nourishment of her developing eggs. It’s no surprise that the males evolved longer legs and an instinct for bedroom bondage.
8. The Shimmering Fossils
Generally, spiders do not fossilize well due to their soft bodies, which decay quickly after death. On rare occasions, amber preserves some specimens. But in 2019, paleontologists made an extraordinary discovery. While excavating in South Korea, they uncovered 11 spiders fossilized in shale. While the number of arachnids was remarkable, there was something even more special. Despite being 110 to 113 million years old, the eyes of two spiders still sparkled.
Spiders, along with other nocturnal animals, possess structures called tapetums in their eyes. These structures function like mirrors, reflecting light through the retina to enhance night vision. The discovery of these sparkling eyes marked the first time tapetums had been found in the fossil record. Their shape, resembling tiny canoes, may help scientists place these fossils on the spider family tree. However, another mystery persists: how did the spiders, and their tapetums, get preserved in the shale?
7. Spider Death Threats
On New Year’s Day of 2019, a passerby was startled by a disturbing scene. As they walked past a house in Perth, Australia, they heard a toddler screaming. Then, a man’s voice repeatedly shouted, “Why don’t you die?” Concerned for the child’s safety, the witness called the police. When the authorities arrived, they expected to find domestic violence. Instead, they discovered a terrified man.
It turned out that the homeowner, who had a severe fear of spiders, had encountered one. The “Why don’t you die?” death threats were aimed at the spider, which the police confirmed was the only one who suffered injuries. While the species was not disclosed, the man’s reaction was not entirely unreasonable. Some of the most venomous spiders in the world inhabit Australia, which isn’t exactly reassuring for someone suffering from arachnophobia.
6. A Legendary Sea Journey
The Australian trapdoor spider (Moggridgea rainbowi) is found only on Kangaroo Island. Initially, it was believed that this species shared a common ancestor with South African trapdoor spiders, with their lineage splitting when Africa detached from the supercontinent Gondwana about 95 million years ago. However, studies revealed that the divergence actually occurred between two to sixteen million years ago. This also eliminated the theory that humans introduced them to Australia. The only plausible explanation left is that the trapdoor spiders somehow floated to Australia.
Initially, the idea seemed implausible. After all, a vast stretch of ocean separates Kangaroo Island from South Africa. Yet, a significant clue supported the theory of an epic journey. Related trapdoor spiders were found on the Comoros islands, just a few hundred miles from South Africa. These spiders likely took a similar trip—by rafting across the sea. If a colony had been swept away by the waves on a floating piece of land, the environment would have been perfect for them. Trapdoor spiders don’t require much space. They create burrows near their mother’s nest, seal them with a protective “door,” and live there for the entirety of their lives.
5. The Electric Highway
At times, spiders create silk parachutes and take flight. Although the phenomenon of ballooning had been well-documented, it wasn’t until 2018 that researchers discovered electric fields trigger this behavior and provide lift even in the absence of wind. The atmospheric potential gradient (APG) was long suspected to be involved. This electric circuit exists between Earth and the ionosphere.
To test this hypothesis, lab experiments exposed spiders to electric fields. When the artificial electric field was turned on, the spiders began ballooning. Surprisingly, the electrostatic forces were enough to push the small travelers along their way. This same phenomenon is responsible for making your hair stand up after rubbing a balloon on your head. When the field was turned off, the spiders gently landed.
It is believed that spiders detect electricity in the air using specialized hairs called trichobothria. This could explain why they tend to balloon more during thunderstorms, which amplify the APG. Indeed, some arachnids have been observed drifting as high as 4 kilometers (2.5 miles) and traveling vast distances.
4. The First Trained Spider
Kim, the spider, may not be the world’s best-trained pet, but she earned a special distinction as the first arachnid to leap on command. Training her to jump when and where scientists asked proved to be challenging, and her three classmates never quite grasped what the humans wanted. Kim graduated in 2018 after successfully leaping between platforms, offering researchers valuable insight into the behavior of jumping spiders, particularly how they jump depending on the distance, direction, and purpose of the leap.
Kim was a regal jumping spider, renowned for her long-distance jumps that she used for hunting, traveling, and escaping threats. She was filmed completing 15 jumping tasks, with the footage analyzed in slow motion. Additionally, a 3-D model of Kim was created to study the physical mechanics of her jumps. The most surprising discovery was that during takeoff, Kim’s legs bore a force of up to five times her body weight. Moreover, Kim was able to anticipate her landing and adjust her leg positioning, jumping higher for long distances and lower for nearby platforms.
3. Graphene Silk
Spider silk is known for its impressive tensile strength, rivaling that of alloy steel, and surpassing most artificial materials in durability. Recently, Italian scientists discovered a way to enhance its toughness even further. By having spiders spin silk containing graphene, they achieved remarkable results. The process was surprisingly simple: spiders from the Pholcidae family were misted with water containing graphene flakes or carbon nanotubes. When the spiders began to weave their silk, the material was tested and found to be the strongest fibers ever recorded.
This “carbon-fiber” silk is a blend of traditional spider silk and graphene or nanotubes. While scientists have confirmed the presence of these materials in the fibers, they are still unclear about the exact process behind it. It's unlikely that the silk was coated with these substances, as a coating alone wouldn't have enhanced the silk’s strength so significantly. The prevailing theory is that the spiders ingested the graphene-laced water, incorporating it into their silk, placing the graphene or nanotubes within the center of the fibers, making them extraordinarily strong.
2. Mysterious Spider Milk
Spider silk is a well-known marvel, but in 2018, scientists noticed an even stranger phenomenon: spider milk. While studying a jumping spider called Toxeus magnus, researchers observed three unusual behaviors. Typically, this species doesn’t form colonies, yet nests were found filled with adult juveniles. Surprisingly, newly hatched babies never left the nest, and the mother never brought them food. Despite the odds, they survived for 20 days without nourishment, only to eventually venture out to forage for themselves.
The third behavior was the most peculiar of all. Occasionally, one of the juvenile spiders would attach itself to the mother. She appeared unfazed by this and even showed tenderness toward the young one. Upon closer inspection, it became clear that the mother was providing her offspring with a form of milk, continuing to nurse them even after they had started to find their own food. The composition of this milk was astonishing—rich in fat and sugar, it was four times higher in protein than cow's milk. Although it was excreted, it wasn't milk in the mammalian sense, leaving its true nature a mystery.
1. Number 16
In 2016, an extraordinary spider celebrated her 43rd birthday. Known as Number 16, she was a trapdoor spider living in the wild. Discovered as a baby in 1974 in Australia's North Bungulla Reserve, researchers monitored her nest for decades as part of an ongoing study. She lived through monumental events like Watergate, the launch of IBM's first personal computer, and the rise of the World Wide Web. At the time of her death, she was the oldest spider known to science.
Although Number 16's body was never found, researchers did not need to search for it in 2016. The telltale signs were clear: her burrow's lid had been pierced by a parasitic wasp. This type of wasp lays eggs inside a spider, and the larvae then consume the spider alive. Despite this tragic end, Number 16's decades-long contribution to the study of trapdoor spider behavior remains invaluable.
