Hermit crabs find new homes in plastic waste: Shell shortage or clever choice?

Enlarge / Scientists have found that hermit crabs are increasingly using plastic and other litter as makeshift shell homes. (credit: Luis Diaz Devesa/Getty)

Land hermit crabs have been using bottle tops, parts of old light bulbs and broken glass bottles, instead of shells.

New research by Polish researchers studied 386 images of hermit crabs occupying these artificial shells. The photos had been uploaded by users to online platforms, then analyzed by scientists using a research approach known as iEcology. Of the 386 photos, the vast majority, 326 cases, featured hermit crabs using plastic items as shelters.

At first glance, this is a striking example of how human activities can alter the behavior of wild animals and potentially the ways that populations and ecosystems function as a result. But there are lots of factors at play and, while it’s easy to jump to conclusions, it’s important to consider exactly what might be driving this particular change.