Lizard heads called the parietal eye, a basal ("primitive") feature also present in the tuatara. This "eye" has only a rudimentary retina and lens and cannot form images, but is sensitive to changes in light and dark and can detect movement. This helps them detect predators stalking it from above. Until 2006 it was thought that among lizards, only the Gila monster and the Mexican beaded lizard were venomous. However, several species of monitor lizards, including the Komodo dragon, produce powerful venom in their oral glands. Lace monitor venom, for instance, causes swift loss of consciousness and extensive bleeding through its
Arizona night lizard young of the lizard are born live, usually one or two around August or September. As the lizard tends not to move about and generally avoids humans, not much is known about it. The species grows to maximum size of about 10 cm. The head is covered with large, smooth plates. Body scales are small, while belly scales are rectangular. The dorsal side is covered with many small dark spots tending to form rows. The eyes are large and round with a vertical pupil (similar to a snake's eye). The species is a secretive lizard. It feeds, reproduces, and lives