Ghost Crabs Take Stomach Growling to a Whole New Level

Ghost crabs produce a unique rasping sound using teeth in their stomachs, a behavior discovered in a 2019 study. This sound serves as a warning, freeing their claws for defense. The gastric mill, typically used for grinding food, is repurposed for sound production. Researchers used laser Doppler vibrometry to confirm the sound's origin. The study highlights evolutionary adaptation, where existing structures gain new functions. This phenomenon is not unique to crabs, as other animals also repurpose body parts for communication.

Why is it advantageous for crabs to use their stomachs for growling instead of their claws?

What does the study suggest about the evolution of communication methods in animals?