Appearance of Iguanas While there are many wild iguanas in Southern and Central America, green iguanas are the most common in the United States. They can reach up to six feet long from head to tail and weigh about eight to seventeen pounds. Although their name states otherwise, the pests can differ in color from dark gray or pale brown to bright orange or dull green. Along with comb-like spines that run across these reptiles' backs, they are covered in scales and have a membrane that hangs underneath their jaws. Detection & Identification Although these pests have a unique look, they are commonly confused with other reptiles. For example, because of its dark color, a species known as the spiny-tailed iguana is frequently identified as an alligator by mistake. In fact, they are much smaller than adult alligators. Though iguanas are frequent invaders of yards, they are not aggressive towards people unless they feel threatened. The massive lizards enjoy basking in the sun in grassy areas, along driveways, and near seawalls. Iguana Issues & Control Iguanas will strike with their powerful claws, tails, and jaws when provoked. They can also cause foundations, driveways, and seawalls to crack or collapse when they burrow underneath. In addition to destroying landscaping by feeding on plants, trees, and other foliage, the reptiles leave odorous droppings wherever they sunbathe. Iguana poop can contain and spread Salmonella, a major cause of food poisoning. Because it is illegal to relocate wildlife in some areas, homeowners should contact the experts at Critter Control to safely manage iguana problems..