Do all spiders weave webs?

Although webs are the most well-known use for spider silk, not all spiders make webs to catch their prey. In fact, less than half of the 37 spider families in Britain do.

However, even spiders that don't make webs have uses for silk, including creating moulting platforms, sperm webs for males, and retreats.

Jan adds, 'Jumping spiders, for example, make little silken cells in which to hide in during the day - a bit like a sleeping bag.'

Most spiders use silk to wrap their eggs. Ballooning is another spectacular use for silk, allowing the mass dispersal of spiderlings and small adults.

Spiders that don’t build webs catch their prey by other means,  such as ambushing it from a hole in the ground (like trapdoors spiders), or stalking it and leaping on it (like jumping spiders). Those that don’t construct webs still use silk, but for other purposes. These include building retreats, safety drag-lines (constantly connected as the spider moves around) and for dispersal in a process called ballooning. One of the most common uses of silk in the spider world is in the construction of egg sacs that are used to protect their eggs.  

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What did ancient Greeks use for bandages?

Did you know spiderwebs were used as bandages to treat injuries in ancient times? Spiderwebs are made of spider silk. They were believed to have antiseptic and anti-fungal properties. They helped prevent infection and were said to promote clotting of blood. Now research in spider silk is going on all over the world to explore its relevance to areas of medicine and industry.

If you are in midst of a forest, and get cut by a machete and there’s profuse bleeding, what do you do? You find a cobweb. Funny as it may sound, putting a bunch of cobweb on your wound will make the blood coagulate much faster. Thanks to those thousands of strands of nanowires which act as nucleation lines.

Besides that, since the cobwebs are proteins basically, they are good places for fungi and bacteria to grow. So, the spider knows that and has evolved to keep these bacterial and fungi growths away from its web. Cobwebs are in fact antiseptic and antifungal too. As long as the web is clean, it will not cause any kind of infection if you put it on an open wound.

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What are the fun facts of tarantula?

It belongs to a group, which consists of 700 species of hairy spiders. Unlike most spiders, it does not spin webs to catch prey, rather use silk to secure the entrance to its burrow. It typically lives in the ground.

It is a night-time hunter. It uses its legs to catch prey, which includes insects. Some of the bigger tarantula species enjoy frogs, toads and mice.

After catching a prey, it injects paralyzing venom into it. It secretes digestive enzymes to liquefy its body and drink it using its straw-like mouth openings.

It defends itself by throwing needle-like, barbed hairs at its attackers.

One of the most distinctive traits of many tarantulas is the presence of bristly hairs on their bodies, including their legs. Although this looks like hair and is commonly described as such, spiders and other arthropods do not have true hair like mammals do. Mammalian hair is mainly made of keratin, while arthropod setae consists largely of chitin.

Tarantulas are long-lived spiders, although their life spans vary by sex as well as species. Male tarantulas may live for as long as 10 years, but once they successfully mate, they usually die within a few months. Female tarantulas, on the other hand, have been known to live for 30 years.

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What is arachnida?

Arachnida is a class of joint-legged invertebrates with segmented bodies, tough exoskeletons, and joint appendages. Arachnida includes orders containing spiders (the largest order), scorpions, ticks, mites, harvestmen, and solifuges.

Almost all adult arachnids have eight legs, unlike adult insects which all have six legs. However, arachnids also have two further pairs of appendages that have become adapted for feeding, defense, and sensory perception. The first pair, the chelicerae, serve in feeding and defense. The next pair of appendages, the pedipalps, have been adapted for feeding, locomotion, and/or reproductive functions. In Solifugae, the palps are quite leg-like, so that these animals appear to have ten legs. The larvae of mites and Ricinulei have only six legs; a fourth pair usually appears when they moult into nymphs. However, mites are variable: as well as eight, there are adult mites with six or even four legs.

Like all arthropods, arachnids have an exoskeleton, and they also have an internal structure of cartilage-like tissue, called the endosternite, to which certain muscle groups are attached. The endosternite is even calcified in some Opiliones.

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There’s music in spider webs, say MIT researchers

Spiders are fascinating creatures. Master builders who expertly weave strands of silk into intricate webs, spiders use these both as their home and their hunting grounds. Human beings have been enthralled by the spider's ways and there have been many who have wished to enter the spiders world to learn more about web construction and arachnid behaviour.

Notes from the web

In April 2021, a group of researchers from Massachusetts Institute of Technology (MIT) along with collaborators at Studio Tomas Saraceno reported a way of translating the structure of spider's web into music. As spiders live in an environment of vibrating strings with different frequencies, which they use to sense the world around them, researchers decided to extract these rhythms of non-human origin and convert them to music.

In order to achieve their objective, a laser was used to capture the spider web. The 2D cross-sections thus obtained were then reconstructed into a 3D web network using the aid of computer algorithms. Next, different frequencies of sound were assigned to each strand of a web, thereby creating notes. These were combined based on the web's patterns to create melodies. By creating a harp-like instrument, the researchers then played the spider web music in a number of live performances around the world.

3D printing

Apart from the wow factor that such a research provides and the fact that it could act as musical inspiration as well, researchers have identified a number of other uses that might come in handy. After gaining insights into how spiders build their webs, the step-by-step knowledge could be used in constructing 3D printers that mimic these spiders and hence might be able to build complex electronic circuits.

Communication with spiders

Additionally, these experiments showed that an algorithm was able to correctly classify spider sounds into different activities, even though they sounded similar to human ears. This means that the time when human beings learn how to communicate with spiders in their own language may not be that far away!

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