Field experiment on the response of spiders to polarized light

This video was taken as part of an experiment on the role of polarized light on spider navigation.

A sheet of polarizing film was suspended above the water roughly 1m from shore.

A spider was dropped onto the water's surface halfway between the film and shore and the spiders choice (under the film or shoreline) was recorded.

The red box highlights the approximate area underneath the film.

An equal number of spiders chose the area under the film as did dry land.

This experiment confirmed that spiders can likely see polarized light reflecting off the water surface and use the absence of that light on shore to tell where the nearest dry land is located.