Underground Castles? How Desert Spiders Craft Vertical Tunnels

By Mindy Weisberger

Beachgoing sandcastle builders know the exquisite frustration of tunneling into sand that’s too dry. The tunnel simply won’t hold its shape and quickly collapses.

But some types of desert spiders have mastered the technique of working with dry sand, excavating subterranean burrows — a few grains of sand at a time — that somehow retain their form and withstand pressures from wind and the shifting weight of the sand around them.

In a new study, scientists closely observed four species of desert spiders known to excavate vertical sand tunnels for hiding, resting and breeding, in order to dig up their engineering secrets. Unexpectedly, the researchers discovered that the arachnids used different yet equally effective methods for collecting and moving sand while they worked, and they strengthened the tunnels as they dug with carefully laid supporting layers of silk webbing.

Burrow-dwelling spiders like those in the study are strictly nocturnal. For the scientists, that meant spending long hours crouched in sandy environments with a flashlight, the study’s lead author Rainer Foelix, an arachnologist at the Neue Kantonsschule Aarau in Switzerland, told Live Science in an email. 

Continue reading by clicking the name of the source below.