{"id":510613,"date":"2026-05-30T17:19:10","date_gmt":"2026-05-30T17:19:10","guid":{"rendered":"https:\/\/www.europesays.com\/ie\/510613\/"},"modified":"2026-05-30T17:19:10","modified_gmt":"2026-05-30T17:19:10","slug":"streetlights-are-trapping-thousands-of-isopods-in-mysterious-death-spirals","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/ie\/510613\/","title":{"rendered":"Streetlights Are Trapping Thousands of Isopods in Mysterious \u201cDeath Spirals\u201d"},"content":{"rendered":"

\"Armadillo<\/a>Habitus of isopods collected during aggregative behavior in Eliad. Credit: Idan Sheizaf, Ariel Chipman, and Eviatar Itzkovich<\/p>\n

Artificial streetlights can lure isopods into massive circular processions that may leave them vulnerable to predators.<\/strong><\/p>\n

Researchers have made a world-first observation of thousands of Israeli isopods leaving their normally solitary shelters and moving together in huge synchronized \u201cdeath spirals\u201d caused by artificial streetlights.<\/p>\n

By testing different light arrangements, the team found that vertical beams of white light can unintentionally override the natural behavior of these crustaceans, pulling them into a circular march that is striking to watch but may put them at risk. The finding reveals another hidden consequence of light pollution for small animals that live close to the ground.<\/p>\n

A new study led by PhD student Idan Sheizaf, under the guidance of Prof. Ariel Chipman from The Hebrew University of Jerusalem, has described a behavior never previously documented: thousands of land-dwelling isopods moving together in large circular processions. The behavior appears to result from artificial light at night.<\/p>\n

Published in Ecology and Evolution, the study examines how these small terrestrial relatives of crabs and shrimp, also known as \u201cwoodlice\u201d or \u201cpill bugs\u201d, leave their usual sheltered habitats and gather in swirling \u201cmills\u201d that can contain more than 5,000 individuals.<\/p>\n

A Chance Discovery in the Golan Heights<\/p>\n

The unusual behavior first reached the researchers through amateur naturalist Eviatar Itzkovich, who noticed the moving circles on summer nights in the Golan Heights. The study focused on Armadillo sordidus, a species that, like most isopods, usually stays beneath stones or in moist debris to avoid drying out.<\/p>\n

Woodlice are known to cluster together to retain moisture, but coordinated movement on this scale has almost never been recorded. Before this research, very little was known about A. sordidus. The study also broadened the species\u2019 known range. Previously, it had been recorded only in southern Syria and the Golan Heights, but this work marks the first description of the species in the Jezreel Valley.<\/p>\n

Testing the \u201cLight Trap\u201d<\/p>\n

To identify what was causing the behavior, the team tested several possible environmental triggers, including magnetic fields and different kinds of light.<\/p>\n