This 2pc round shaped rattlesnake eggs rely on their magnetic force to merge together creating a startling sound effect. Not only are they fun to play with, but they are also great for hand-eye coordination. They dance, spin and even "sing"! When you toss them in the air the two hematite magnets fly and collide, wrestling for equilibrium in a clattering, buzzing, Cicada sounding collision until they land at rest.