Doves are slim birds that can fly quickly over fields and forest. When doves search the ground for seeds or sometimes insects, they nod their heads like pigeons. Males woo females by chasing them, bobbing their necks in time with their coo-coo-cooing. Doves lay one or two eggs in small nests. When the eggs hatch, both males and females feed the nestlings something called crop milk, a high protein high-fat food that they secrete in their crops or the pouches under their throats. The milk is gradually replaced with seeds. Legend has it that after the flood Noah released a dove. When it returned carrying an olive branch in its beak, Noah knew that there was still dry land somewhere on earth. Since then, a dove with an olive branch has been a universal symbol of peace.