Carnivorous plants often claim the name 'insectivorous' for the simple reason that most carnivorous traps usually contain insects, and, even when not insects, trapped prey are usually close cousins of the insects from within the Phylum Arthropoda. An example of this is when bladderworts (Utricularia spp.; Lentibulariaceae) trap crustaceans such as amphipods and copepods, which are arthropods, like insects. Indeed, Darwin's book on the carnivorous plants recognizes this fact with its title Insectivorous Plants. Splitting open a pitcher from Sarracenia leucophylla, as an example, usually reveals one chitinous arthropod exoskeleton after another.