Why Do Some Spiders Make Web Art? | Defector

"But some spiders take web design a step further. After spinning spokes and spirals, certain arachnids might add a cross made of zig-zagging lines, or a latticed nebula that radiates out from the center of the web. These embellishments, called stabilimenta, are spun with the toughest type of spider silk, known as aciniform silk, the kind they use to cocoon and immobilize prey. And though their beauty is clear, their purpose is hazy."

"As such, scientists have long speculated about why, exactly, a spider might go and do something like this. Surely there must be some benefit that outweighs the downside of visibility, and warrants the tremendous physical effort of going so ham on decorations. "No one has fully understood its function," said Gabriele Greco, a researcher at the Swedish University of Agricultural Sciences in Uppsala, who self-describes as a physicist who is in love with spiders."

Many spiders build radially symmetric webs of spokes and spirals that glisten with dew. Some species add conspicuous embellishments called stabilimenta, often woven from tough aciniform silk used for cocooning and immobilizing prey. Stabilimenta form crosses, zig-zags, or latticed nebulae that radiate from web centers. The strands are stark white and visible in ultraviolet, which increases conspicuousness and could attract predators. Scientists propose multiple, nonexclusive functions for stabilimenta including prey attraction, light scattering, shading to reduce spider temperature, warning birds to avoid webs, and predator deterrence, but no single function is conclusively established.

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