Reptiles occupy a variety of habitats ranging from grasslands to rocky slopes and play an important role in maintaining the health of an ecosystem. They consume large quantities of insects, spiders, scorpions, small mammals, and other reptiles, thereby preventing infestations of any single species. Respecting the entire reptile community helps to preserve this vital link. All reptiles are "ectothermic," or cold-blooded, regulating body temperature via external sources rather than internal metabolism.
The metabolic rate of a reptile is very low, but so are its energy needs. Keeping warm in the Arizona sunshine does not require much work, so energy generated can be used for reproduction and finding food instead of for heating and cooling. Of course, there are limitations to this type of adaptation. Since they cannot pant or sweat, reptiles are not able to endure extremely high temperatures without shade. They also cannot endure freezing temperatures. When it is cold, they hibernate or enter into an inactive torpor. When lizards are seen scurrying across a rock or path, please resist the urge to catch them. Lizards can have a mean bite and some will actually shed a tail to escape capture. Though the tail will grow back, a great deal of body energy is used in the process and population dynamics will be affected. Enjoy them from a respectful distance.