Did you save a spider this week?
Save a Spider Day is celebrated every March 14, and it is the world’s chance to stop, appreciate, and maybe even rescue the tiny (and sometimes a bit bigger than tiny), eight-legged, silk-spinning arachnids. Crawling, climbing, and ballooning around the world are 46,000 different species of spiders, all of which produce venoms made up of many different toxins, and all of which can spin liquid protein into silk that they use for everything from catching their prey to protecting their young. Our two resident Chilean rose tarantulas had a busy week celebrating by traveling to schools around Maine to teach students about spiders and other arthropods.
If you find yourself cringing away from your screen rather than stopping to appreciate the beauty of this delicate pink lady, fear not! Although only about 200 spider species pose a threat to humans and the vast majority of spider venom is meant only to kill or stun their insect prey, spiders scored first place on a list of the animals most feared by humans. This may be an innate fear many of us are born with, as some psychologists believe we have evolved to be hyper-aware of spidery shapes and erratic movements.
Whether you are one of the 6% of the population with arachnophobia, or you are a lover of all things creepy and crawly, there are many reasons to appreciate spiders, as they have been benefitting and inspiring humans throughout history in some very unexpected ways.
Feasting on Foes
Before evicting a spider who’s moved into a corner in your house, consider that in just one year a hungry spider can eat 2,000 insects and other pests that would otherwise infiltrate your home. Spiders as a whole consume 400 to 800 million tons of insects annually. For an idea of just how much that is, consider that humans only eat about 400 million tons of meat and fish each year, or that whales eat a measly 280 tons of seafood. One of a spider’s favorite things to snack on is a tasty mosquito, one of the deadliest animals in the world thanks to the diseases they transmit between humans. In 2015, deaths from malaria alone totaled 438,000, while the number of deaths from spider bites topped out at about 50. A tiny house spider hanging in a corner is most likely doing far more than you realize to earn her keep.
Pumping up robot designs
The unique way in which spiders crawl and climb, while sometimes off-putting to humans, is powered by an efficient hydraulic pressure system that has inspired some roboticists in the design of their robots. Part of the reason that spider movement tends to creep us out on an instinctual level is that spiders move very differently from other limbed animals. Many animals have muscles that allow them to move their limbs in more fluid motions; spiders, on the other hand, have muscles that allow them to move their legs inward, but all outward motions of their eight legs are controlled by hydraulic pressure. The pumping of hemolymph from their central body out toward their limbs lends their movements a robotic quality that can appear jerky and erratic to us. This movement has been adopted, however, by some emergency surveying robots that are designed with a spidery shape and hydraulic motion system that allows them to travel over uneven terrain and debris without tipping over.
Bringing us closer to the stars
Spider silk is incredibly strong: pound for pound, it is as tough as steel and much more flexible. Spiders are capable of spinning different types of silk depending on their needs. Some spiders can spin up to seven different kinds, which they use for catching prey, wrapping up their meals, ballooning or traveling, forming egg sacs, and more. Although natural spider silk is difficult to farm in large quantities, the strength and flexibility of this natural protein fiber is so impressive that it has inspired the engineering of synthetic spider silk (and the genetic engineering of goats that produce synthetic silk in their milk!) that has been used for a range of things from medical bandages to bulletproof vests. For two and a half centuries, tiny pieces of super fine spider silk were even used to form crosshairs in eyepieces, rifle scopes, and telescopes to allow humans to accurately gauge distances.
Spiders have been unsung heroes living among humans for millenia, so the next time you come across an eight-legged friend, perhaps think twice before smushing her and thank her instead!
Please visit https://tnhp.chewonki.org/ if you would like to meet our friendly tarantulas and learn more about the fascinating lives of spiders and other arthropods.