With its massive tail and iridescent colors, this bird has long fascinated its human observers and were still learning its secrets. For example, astudyrecently published inThe British Journal of AnimalBehavioursays that when a peacock fans its ornamented train for the ladies during mating season, its feathers quiver, emitting a low frequency sound inaudible to human ears. Depending on whether they wantto attract females from far away or up close, they can change the sound by shaking different parts of their feathers. (Theyre not the only animals that create infrasonic sounds. Elephantsproduce themwith their vocal cords, most likely to communicate overlong distances.) Here are a few other interesting facts about theseimpressive birds.