Jerusalem Crickets - scary looking, but harmless.
As a group of us were walking along a path at #scicommcamp, we stumbled upon a gigantic bug! At first, it almost looked like a giant ant, or maybe a bee of some kind. But on closer inspection, it didn't have any wings, and instead had a giant (and creepy-looking) set of chompers. It turns out that it was a Jerusalem cricket!
The first cool thing about these critters is where they got their name. Since they are common to the American west, the common name for them is a Navajo term ("yo sic’ini") meaning "skull insect." Makes sense when you see a picture of these guys. Apparently Franciscan priests overheard this name, and thought that the Navajo were referring to "Skull Hill" (aka Golgotha) - a site in Jerusalem where Jesus was crucified.
The second cool thing about Jerusalem crickets is that, unlike true crickets, which create their "song" by rubbing their wings together, Jerusalem cricks are born drummers. When mating, they drum out a sick beat by thumping their abdomen on the ground. (Is it just me, or does this remind anyone else of the knocking from Doctor Who?)
Here's something else - insects in general are covered in ears (but typically don't have any on their head). Crickets in particular have eardrums (called subgenual organs) located in their knees. They use these eardrums to detect vibrations with extreme sensitivity. Crickets are sensitive to ground movements, and can detect just 1nm of displacement in the ground! This was probably developed in response to predators such as bats; their extremely sensitive eardrums allow them to not only hear bats coming, but can detect their mid-air movements!
When one of our #scicommcamp attendees tried to pick up the cricket we found, she thought at first that it was biting her! But more likely, he was just scurrying across her hand with its super-spiky legs! Since these guys spend most of their time underground, they have become very good at digging.