The male then partly enters the burrow and drums the edge with his claw. Other facts about fiddlers Challenges from other fiddler males rarely result in direct combat, since a fight could severely damage both crabs. Adult fiddlers molt once or twice a year. During its soft-shelled period it remains near or in its burrow. If an adult male loses its fiddler claw, the remaining claw grows to the same size as the lost claw, the claw it regenerates becomes the smaller claw.
Fiddlers have compound eyes, a little like a fly's, attached to eye stalks.
A recent study conducted by John Layne at the Duke University Laboratory in Beaufort, NC, indicates that for the fiddler, the visible horizon is the animal's main point of reference, and fiddlers seem to respond not to the shape or size of a particular predator but to where the object or thing appears in relation to its visual horizon. If the thing appears at or beneath the horizon, it is either treated as the same species or ignored.