The American Woodcock is seldom seen, for its protective coloring renders it virtually invisible against a background of dried leaves. When flushed from underfoot, it zigzags off through the brush with a whistling of wings. Those fortunate enough to live near their breeding grounds may see woodcocks perform their courtship flight in early spring each year. In these spectacular aerial displays, the male spirals up to a considerable height, circles, then plummets down to earth, twittering as he descends. Woodcocks subsist chiefly on earthworms, which they extract with their long bills; the tip of the upper mandible is flexible so that they can grasp a worm while probing in mud without opening the bill. Insect larvae and occasionally vegetable matter are also eaten.