Reptile Behavior in Self-Defense

Reptile behavior can be a fascinating subject. We are beginning to understand that many of the behaviors we see in captive reptiles may have specific functions.


One of the most well known defensive displays by snakes is tail displaying. This is common in pipe snakes, shield tailed and ring necked snakes as well as burrowing pythons and sand boas.

Threat Displa게코도마뱀 ys

The term threat displays describes a group of behaviors that include lunging, growling, snarling, snapping and biting. They are used by animals to resolve territorial and resource disputes, to communicate their strength or condition, or to escape threatening situations. A variety of display behaviors can be observed in reptiles including gaping, head shaking, puffed-up body and tail waving. Whether these threats are effective in resolving conflicts is difficult to determine. Threat displays reveal information about the contestants such as their size, fighting skill and current condition. In addition, they can also serve to communicate the contestants’ intentions and the potential outcome of a fight.

Some snakes, such as coral snakes and shield tailed boas will hide their heads within coiled bodies when threatened. These displays, called deimatic behavior or startle display, can be very effective in bluffing predators and providing prey animals an opportunity to escape.

Other threat displays involve inflating the chest, increasing throat size and hissing. Pine snakes, for example, have a septum at their glottal opening (glottal keel) that serves to amplify the sound of their hissing. This is a very effective threat display for increasing body size and intimidating predators. A variation of this behavior is gaping which involves opening the mouth wide revealing the bright pink oral mucosa and emitting a low guttural hiss. This is a very effective threat and warning display for some reptiles but can also lead to full bites if the animal is not heeded.

Tail Displays

Many reptiles use their tails as a display and to deter predators. This displays a brightly colored contrasting ventral surface (coral snakes, shield tailed snakes) or the tip of the tail that can be waved in the air like a lizard’s head or coiled tightly to mimic a striking snakehead (rubber boas). When this is done it diverts the attack away from the vulnerable head and enables the snake to escape. This behavior is especially common in coral snakes and some other elapids.

When displayed in captivity these behaviors may be misinterpreted as signs of disease or injury. For example, when a monitor or rat snake performs a threat display by raising its head from a crevice or burrow it is actually increasing heat uptake through the skin by hormonally controlled darkening (melanization). If an owner sees this they may incorrectly assume that there is an underlying medical condition.게코도마뱀

Another example occurs with a pair of iguanas that have established dominance hierarchies and are competing for the attention of the female in the group. A male will bob its head, lash its tail and strike the neck of the female to achieve dominance. If the human interprets this behavior as aggressive and does not leave the iguana’s territory it may escalate into biting attacks. A normal behavior that can be misinterpreted as an indication of illness or a traumatic injury is the balling display of pythons, coral snakes and some other species.

Confined Spaces

Reptiles occupy diverse ecological niches and have evolved to perceive the environment in different ways. Some species live in open areas where hiding spots are scarce, like the nocturnal Catalina Island rattlesnake (Crotalus catalinensis) and diurnal Sonoran spiny-tailed iguana (Ctenosaura macrolopha). Others have more flexible activity patterns, like the boids of Madagascar and the crocodilians that use integumentary organs to detect vibrations and air-borne sounds [1]. The diversity of these behaviors and morphological adaptations makes it difficult for even the most knowledgeable reptile owner or practitioner to generalize their responses to complex stimuli such as visitor effects.

As a result, some alterations to the animal’s habitat or care routine may be perceived by an unsophisticated observer as signs of disease or trauma. For example, a hognose snake’s death feigning behavior is a bluff display that can look to an untrained observer like a nervous response to an actual threat. In fact, if it is not rapidly halted a snake will continue to violently writhe with its mouth hung limply open while secreting urates and feces.

Similarly, the slow-onset changes to a reptile’s coloration, thermoregulating habits, appetite, shedding schedule and taming progression can be mistaken for illness by an unobservant observer. These include increased or decreased tongue-flicking; erratic shedding or sheds that fail to finish; excessive gaping; regression/increased tameness; and abnormal growth (i.e., pyramidal shape of carapaces in African spurred tortoises).


The behavior of a reptile in self-defense is determined in large part by its evolutionary history and the type of threat it encounters. This is true for both physical and psychological forms of defense. Physical self-defense includes fighting or other aggressive behaviors such as threat displays. Threat display is any aggressive communication without direct contact and can include push-up displays, throat expansion or high-intensity erection of the dewlap. Another form of defense is avoidance behavior that allows the animal to remain alert but not reactive to a threat. This is a common defensive response of hognose snakes and false spitting cobras but can be seen in many other reptile species.

Some reptiles use behavioral strategies that can be misinterpreted as a sign of disease or injury. For example, a snake that is attempting to warm up on a cool morning by basking in a crevice or burrow will often expose only its head, which is most sensitive to the sun’s rays. When this occurs the head will darken through hormonally controlled dispersal of melanin. When a pet owner sees this behavior they may interpret it as an indication of injury or disease.

Tail vibration is a well-known defense mechanism of many venomous snakes, but it’s also exhibited by some non-venomous snakes such as the bushmaster (Lachesis muta). This behavior is intended to produce a sound that will deter predators. Inexperienced owners of these reptiles may misinterpret this as an indication of illness or possible neurological damage.