Imagine trick-or-treaters who change masks at every house. But they have only three masks.

That roughly describes the evolutionary experience of the Hawaiian stick spider.

Researchers reported in the March 19 issue of the journal Current Biology that these spiders, part of the genus Ariamnes, have repeatedly evolved into the same distinct forms every time they island-hop.

That is a strange pattern, shared only by another island spider, genus Tetragnatha, and the Anolis lizards of the Caribbean, scientists say.

The stick spiders, 14 species in all, live in forests more than 2,000 feet above sea level on Oahu, Kauai, Molokai, Maui and Hawaii island. Although they’re nocturnal and can’t see very well, they’re still brightly and distinctly costumed.

“You’ve got this dark one that lives in rocks or in bark, a shiny and reflective gold one that lives under leaves, and this one that’s a matte white, completely white, that lives on lichen,” said University of California, Berkeley, evolutionary biologist Rosemary Gillespie in a news release March 15.

These different colorings allow the spiders to camouflage themselves against specific similarly colored surfaces in their respective habitats and avoid their major predator, Hawaiian honeycreepers.

Gillespie thinks the Ariamnes spiders have some sort of preprogrammed switch in their DNA that can be quickly turned on.