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In Photos: Spiders Hatched from Web Towers

Mysterious structure

Nobody knows exactly what this structure is or who made it.

(Image credit: Troy Alexander / Tambopata Research Center)

While volunteering in the Peruvian Amazon, graduate student Troy Alexander discovered a strange web formation underneath a tarp.

Circle and spires

The weird structure was first spotted on the underside of a tarp near the Tambopata Research Center in the Peruvian Amazon.

(Image credit: Troy Alexander / Tambopata Research Center)

The formation, about 0.8 inches (2 centimeters) across, had a strange spire in the middle encircled by picket-fence like posts.

Slime mold?

a yellow slime mold

(Image credit: Image courtesy of Audrey Dussutour)

Experts guessed it could have been a slime mold, a structure made by moths, or a defense made by spiders, but everyone was stumped.

Return to the scene

(Image credit: Jeff Cremer /

So several months later, a team of researchers returned to the site to study the structures. After putting them in a glass, they found baby spiders hatched from the strange structures.

Spider eggs

spider hatched from strange formation

(Image credit: Jeff Cremer /

The mystery was solved: The web towers were used for spider eggs, from which tiny, less than 1 mm spiderlings emerged.

Still unknown

tiny spider hatchling

(Image credit: Jeff Cremer /

But it's still not clear what species of spider made the webs or what the picket-fence circle is for.

Ant defense?

spider hatchling

(Image credit: Jeff Cremer /

One possibility is that the fence is a defense against ant invaders eating or damaging the eggs, or the spikes lure mites as tasty snacks for the hatchlings.

Tia Ghose
Tia has interned at Science News,, and the Milwaukee Journal Sentinel and has written for the Center for Investigative Reporting, Scientific American, and ScienceNow. She has a master's degree in bioengineering from the University of Washington and a graduate certificate in science writing from the University of California Santa Cruz.