The larvae of moths and butterflies are very susceptible to predation, especially by birds, and they utilize many different strategies to protect themselves. Shapes, colors and behavior all contribute to their survival. Some larvae take on the appearance of less appetizing things, such as bird droppings, twigs or leaves. Some have large eye spots which presumably scare predators. Others have cryptic coloration which makes them all but invisible. The pictured green caterpillar uses both color and behavior to visually disappear on the fern it is consuming.