* Clicking: Some crabs, like fiddler crabs, make clicking sounds with their claws for communication or to attract mates.
* Hissing: When threatened, some crabs may hiss by expelling air from their gills.
* Scuttling: The sound of a crab walking, especially on a hard surface, can be quite distinct.
* Snapping: The snapping sound of a crab's claws can be a warning or a sign of aggression.
* Bubbling: Some crabs make a bubbling sound when they are feeding or are underwater.
Ultimately, the "sound" of a crab is more about the noises they make in specific situations rather than a distinct call like other animals.