Spiders - Jumping Spider
Summary: A Spider that can jump up to eighty times the length of its body. Sounds like a myth that might have been invented by Steven Spielberg, but even the creator of the movie Arachnophobia couldn't make up that story about the jumping spider.
Jumping spiders come in assortment of shapes and sizes. There are over five thousand different species of jumping spider, so it is hard to make generalizations about them. However, most of them are small, hairy, and can jump, of course.
They are good jumpers because they can quickly change the pressure of the body fluids in their limbs, so that when their legs stiffen suddenly, the spider is propelled upward. This is different from the opposing muscle groups that humans and mammals use for movement. The spider's movement looks erratic to us because they do not use muscles that flex and un-flex to create their movements. They use a hydraulic system that changes how much fluid is allowed into the leg. Think about a balloon that gets filled with air suddenly, and then loses pressure to relax. Because the jumping spiders are so small, usually shorter than Â½ inch, this sudden change in fluid pressure can catapult them long distances.
With all this leaping about, the jumping spider has not forgotten about safety. Before the spider jumps it uses a piece of silk to tether itself to its jumping off point. That way, if the spider does not make it to the leaf or other elevated location to which it is aiming, all is not lost. The tether will catch the spider like a bungee cord before it hits the ground. Using the tether, the jumping spider can climb back up the thread and try the leap again.
Jumping spiders do not use their webs to catch prey. They build webs for protection while they are molting, and to lay eggs in. The webs are tent-like with feathery silk that is not as sticky as spider silk that is designed to catch prey.
Jumping spiders have excellent vision; the best of any spider. They have eight eyes that are usually arranged in two rows, with a large set of eyes on the front of their face, and smaller eyes on the top of their head. When confronted with something as large as a human the jumping spiders often do not run away as many spiders do, but they watch closely and back up carefully if it gets too close. For this reason jumping spiders are sometimes called bold or daredevil spiders. Of course, they could also be called daredevils because of their affinity for bungee jumping.
Jumping spiders are active hunters. They usually try to jump on their prey. They hunt during the day and will feed on many different kinds of insects. Some jumping spiders even include nectar from flowers in their diet.
Jumping spiders might be found roaming in the home while they are looking for food or a mate. They are not aggressive, but will bite if handled roughly or if they feel threatened. Even the bite of the larger species is not any more painful than a bee sting and will not have lasting complications. If you are bitten by a jumping spider, try to catch it so you can use it for identification purposes, if need be.
Jumping spiders sometimes have crazy shapes that have helped them to adapt to their environment. Some jumping spiders mimic ants to avoid predators or to trick their prey. Some species look remarkably like the species that they are imitating. These spiders' front legs are adapted to look like antennae, and their bodies are narrow like an ant's. There are other species of jumping spider that have flaps between their legs that help them to glide.
If you see a jumping spider in your house you might just want to let it wander away. The chance of it biting you is very small. However, if the thought of spiders in your house creeps you out you can use a piece of tissue paper or the business end of a vacuum to dispose of it. You could also take a note card to gently lift the spider and carry it outside. This has some risks, however, because the spiders can jump. Don't be too startled if the spider you are trying to save leaps a few feet away and tries to scurry off.