The "Daring Jumper"
Phiddipus audax

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Jumping Ability

Phidippus audax
along with the other salticids have a unique ability to jump to attack its prey, whether flying or sedentary. Now I know you have probably tried to swat a bee, or even, try and kill a fly. Most likely you were not successful the first few attempts. These spiders are fast enough and accurate enough with their jumps that they can grab a fly, or bee, right out of the air! Studies on the jumping ability of Phidippus audax has shown that they have the ability to precisely measure distance, and direction of its prey’s position with respect to gravity. They will adjust their take-off velocity to compensate for distance and gravity, which displays another unique ability of these already extraordinary organisms. Remarkably, these spiders can also complete an accurate jump from an upside down position! Research has found they even have the ability to retain the direction and position of their prey. This shows that theses spiders, in a sense, have a memory. This is represented in the occasional detours they will take to their prey, as well as if they missed their prey on the first attempt.

Phidippus audax can jump accurately about 10-50 times their body length accurately and with a velocity of about 80-90 cm/sec. This is comparable again to a basketball player that adjusts his/her velocity of a shot due to their distance and direction from the basket. This spider also has not been shown to glide, or use air resistance, which means their jump is strictly just a jump.
Phidippus audax’s hind two legs have been shown, through various studies, to be the source of most of the propulsion for the jump. The propulsion is provided through a hydraulic type pressure build-up of blood in the spider’s legs. For every jump, Phidippus audax attaches a dragline to the substrate it is jumping from in order to protect it from falling if they miss the jump, and in order to brake if necessary. Not only do they have to jump an accurate distance to their prey, they also have to orient their “catching basket,” or legs, around their prey to make their jump successful. Which is also another complex process that Phidippus audax is able to easily complete (Harland 2000).
The jumping ability of these spiders has been extensively studied and this is only a partial explanation of how these spiders can do such accurate and lengthy jumps. If you would like more information on the process that the jumping spiders go through in order to complete these jumps check out this research paper.

Here is a diagram of the process of their jump.

Okay... I'm a little scared now. Do they actually make more of these crazy, jumping, cat-like, other spider-eating, dancing, scary, yet awesome things? Yup!