Hairy claws make hermit crabs braver, study finds

Hermit crabs scuttling along the UK's coastline may be bolder than they appear, especially those with more sensitive claws, according to new research from the University of Plymouth.

The study reveals that tiny hair-like structures called sensilla on the crabs' claws help them assess their surroundings and decide when it is safe to emerge from their shells.

Crabs with more of these sensory hairs were found to recover more quickly and act more boldly.

The researchers hope their findings will inspire further studies into how sensory traits influence animal behaviour.

Lead author Ari Drummond, a PhD researcher at the university, said: "I was especially intrigued by how hermit crabs use their claws and antennae when re-emerging from their shells.

"The patterns I observed led me to wonder if they might be using their claws to assess environmental risk.

"In a world where species face increasing threats, understanding how animals sense and respond to danger is vital."

The team studied local hermit crabs in the lab, observing their reactions to being startled and later examining their moulted claw tissue under an electron microscope.

This allowed them to count the number of sensilla without harming the animals.

Their findings suggested a link between sensory input and personality, a concept they have called "sensory investment syndrome".

Prof Mark Briffa, senior author of the study, added: "We've long known that animals can behave differently from one another.

"This research suggests that those differences may be rooted in how they sense the world around them."

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