Sun-Animalcule plankton get their name from their tendency to emit light in a sphere around them. The plankton begin as eggs and gradually grow, emitting light and fascinating sounds throughout their entire life cycle. The sounds they make change as they grow from infancy to maturity, growing very quickly until they disappear completely. Sun-Animalcule plankton only emerge in the morning, noon, and evening. Sun-Animalcule plankton lose strength as the night wears on; that is when the crescent-shaped Falcato plankton take their place. The pitch of the plankton changes depending on where they grow.