Army of Sea Urchins? | Planet Earth | BBC
Why the open web links it
A short, engaging clip from Planet Earth showcasing the unusual behavior of sea urchins forming large aggregations.
Linked by 8 independent sites, 2 of them widely read in the 2026-10 crawl of the open web, including ilpost.it, libretexts.org, discoverwildlife.com, elicriso.it, foundbypat.com.