Scott Thompson, age 13, of Albany, New York, for his question:

How did the fiddler crab get his name?

There are several species of fiddler crab, all of them crusty crustaceans that belong to the salty sea. All crabs have eight skinny walking legs, plus a pair of oversized legs armed with bulky claws. Most of them have a matching pair of pincer claws. But the fiddler has one average sized pincer leg and one that seems to be borrowed from a giant crab. As a rule, the right claw is the big one. He squats by the top of his sandy burrow, waving this oversized leg too and fro. He was named the fiddler crab because this motion reminded people of a musician sawing away on a country fiddle.

Actually, he is beckoning    but not to us. He is striving to catch the eye of some female of the rather crowded fiddler crab colony, hoping to coax her into his tunnel. The female has a pair of matching claws and uses both of them to mold her food into swallowable pellets. The males reserves his large fiddle claw for beckoning and manages to mold his food pellets with the smaller claw.