Venom types. Among the major classes of toxin in venoms are: Venom is widely distributed taxonomically, being found in both invertebrates and vertebrates; in aquatic and terrestrial animals; and among both predators and prey. The major groups of venomous animals are described below. Venomous arthropods include spiders, which use fangs — part of their chelicerae — to inject venom; and centipedes, which use forcipules — modified legs — to deliver venom; along with scorpions and stinging insects, which inject venom with a sting. In insects such as bees and wasps, the stinger is a modified egg-laying device — the ovipositor. In
Snake venom the intraspecific evolution of venom. Venoms continue to evolve as specific toxins are modified to target a specific prey, and it is found that toxins vary according to diet in some species. Rapid venom evolution can also be explained by the arms race between venom targeted molecules in resistant predators, such as the opossum, and the snake venom that targets the molecules. Scientists performed experiments on the opossums and found that there were multiple trials that showed replacement to silent substitutions in the von Willebrand Factor (vWF) gene which encodes for a venom-targeted hemostatic blood protein. These substitutions are thought