Lizards can and occasionally do bite humans, though this behavior is not typical and usually occurs under specific circumstances. The vast majority of these reptiles are non-aggressive toward people, with a bite representing a defensive strategy rather than a predatory attack. Understanding the motivations behind this action and knowing which species pose a risk is important for safety, especially for those who encounter wild lizards or keep them as pets.
Understanding Why Lizards Bite
The primary reason a lizard might bite is a perceived threat, making the action almost exclusively defensive. When a lizard feels trapped, restrained, or handled roughly, its natural instinct is to defend itself. This is a common response to handling stress, especially in species not accustomed to human interaction. Territoriality can also be a factor, particularly among male lizards that may view a person’s hand as an intrusion. In captive settings, bites sometimes occur due to mistaken identity during feeding, where the lizard confuses a moving finger for a food item.
Identifying High-Risk Species
The potential danger from a lizard bite varies significantly based on the species’ size and whether it produces venom. Many commonly kept pet lizards, such as geckos, anoles, and bearded dragons, have small teeth and weak jaw strength. Their bites are typically minor, resulting in little more than a scratch or surface puncture.
Larger pet species, like monitor lizards or iguanas, present a greater risk due to their physical capacity for injury. These reptiles possess powerful jaws and sharp teeth or serrated mouth structures capable of inflicting deep lacerations or serious tissue damage.
Only two species worldwide are considered medically significant and venomous: the Gila monster (Heloderma suspectum) and the Mexican beaded lizard (Heloderma horridum). The Gila monster is the only venomous lizard native to the United States. These two species are known for having a strong, tenacious bite, often clamping down and chewing to allow venom to seep into the wound through grooved teeth. The venom is painful and can cause symptoms like localized swelling, nausea, and low blood pressure. Bites from these venomous reptiles are rare and usually occur when the animal is provoked or mishandled. Unlike snakes, there is no antivenom available for these bites, meaning treatment focuses entirely on supportive care.
What to Do Immediately After a Bite
If a bite occurs, the immediate priority is to separate from the animal without further agitating it. For venomous species like the Gila monster, the lizard should be removed quickly, sometimes requiring prying its jaws open to prevent prolonged venom delivery. After separation, the wound should be thoroughly washed with warm water and soap for several minutes.
The primary concern with any reptile bite is the risk of bacterial infection, particularly Salmonella. Reptiles naturally carry Salmonella bacteria, which can contaminate their skin and environment. A bite breaks the skin barrier, increasing the chance of bacteria entering the wound. A clean, dry bandage should be applied after washing.
Medical attention is necessary if the wound is deep, bleeding heavily, or shows signs of infection like redness or pus. Any bite from a large or venomous species, such as the Gila monster or Mexican beaded lizard, requires immediate medical assessment to manage pain and monitor for systemic effects.