Spiders produce different types of silk for different purposes, including draglines, egg sacs, ballooning, building a web and wrapping prey. Much of the silk spiders use to spin webs has a sticky consistency, in order to catch flying insects. It turns out that sticky silk isn’t the only reason spider webs are such efficient insect catchers.
According to scientists at Oxford University, not only is much of a spider’s web silk sticky, but it is coated with a glue that is electrically conductive. This glue causes spider webs to reach out and grab all charged particles that fly into it, from pollen to grasshoppers. Physics accounts for the web moving toward all airborne objects, whether they are positively or negatively charged.
According to Prof. Vollrath of Oxford University, electrical attraction also drags airborne pollutants (aerosols, pesticides, etc.) to the web. For this reason, it’s been suggested that webs could be a valuable resource for environmental monitoring. (Thanks to Elizabeth Walker and Linda Fuerst for introducing me to this phenomenon.)
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