Desert Spiders Are the Masters of Building Sand Castles
Every child knows the frustration that comes with painstakingly building a masterpiece of a sand castle at the beach only to have it suddenly crumble and fall apart. The sand is too dry and simply won’t hold the elaborate shape long before collapsing into a massive heap of shapeless sand in front of you. Some desert spiders, however, have been able to master the art of working with dry sand, creating vast subterranean tunnels and burrows out of only a few grains of sand at a time. These vast underground sand castles are somehow able to retain their form. They are so carefully engineered that the pressure of the wind blowing the sand above these underground castles and, in turn, the shifting weight of the sand surrounding the structure.
Researchers observed four different species of these desert spiders that build these elaborate homes in a new study to try and discover their engineering secrets. They found that each species had a different method to deal with building their homes in soft sand, but that they all were equally effective. The cartwheeling spider, also known as Cebrennus rechenbergi, used a method similar to how people build a well to excavate its tunnels. The spider slowly digs a hole in the surface and then secures it with a ring of silk, similar to when people will add a tin sheet to the holes they dig for wells that stabilize them. The spider does this continually, digging farther into the sand and then reinforcing the hole with spider silk until their burrow is complete. It seems that spider silk is what we need to build better sand castles at the beach.
Of course, this requires the spider to move quite a lot of sand without it crumbling in their arms. The cartwheel spider uses the long bristles that fringe its pedipalps and chelicerae to form a kind of mesh basket to hold the sand in and hold the grains together while its being removed. Another species of desert spider used its spider silk to bind the sand together and make it easier to carry out and away from their burrow. In fact, each spider seemed to have its own solution for keeping the sand clumped together so they could carry it away. Maybe these desert spiders can teach us a thing or two about engineering, improving our own methods of building new a better architecture.
How else might one of these desert spiders securely build their underground tunnels in soft sand? Is there a method you use when building a sand castle at the beach that might work as well?