Escape Hatch: The Tough Choices of Treefrog Embryos

Boston University biologist Karen Warkentin has found that red-eyed treefrog embryos are capable of assessing a variety of threats in surprising ways, and if danger presents itself, they can choose to hatch days earlier than they typically would. The process is called environmentally cued hatching, and in the last decade researchers have found evidence that it works for all kinds of animals—from flatworms and snails to fishes, from frogs and salamanders to turtles and birds.