Newts are small, usually bright-coloured semiaquatic salamanders of North America, Europe and North Asia, distinguished from other salamanders by the lack of rib or costal grooves along the sides of the body. Newts have the ability to regenerate limbs, eyes and spinal cords. The cells at the site of the injury have the ability to de-differentiate, reproduce rapidly, and differentiate again to create a new limb or organ. Many newts produce toxins in their skin secretions as a defense mechanism against predators. Taricha newts of western North America are particularly toxic; the Rough-skinned Newt (Taricha granulosa) of the Pacific Northwest produces more than enough tetrodotoxin to kill an adult human foolish enough to swallow a newt. In order to cause harm, the toxins have to enter the body by being ingested or entering a break in the skin.