Reptile Behavior

Reptiles have a wide variety of behaviors and structural morphologies that can help them to evade notice, defend themselves, reproduce and obtain food. These behavioral patterns may be normal but to the casual observer can look atypical and may be perceived as a sign of disease or trauma.


For example, many snakes especially monitors and rat snakes will flatten their heads in a display that can be misinterpreted as respiratory disease.

Social Behavior

Social behavior is a complex suite of interactions that can range from simple feeding aggregations to mating swarms and familial groups with cooperative brood care. It is often viewed as the opposite of aggressive behaviour, but the concept of social interaction does not necessarily mean amicable cooperation toward some mutually beneficial end. Instead, it is more likely that the social behavior evolved to protect the individual from predators, other individuals or the environment, and enables it to reproduce successfully.

Reptiles are known to form these aggregations, as well as engage in complex courtship and parental behavior. They may also compete with others in the same species for territory and mates. Whether an individual snake gives off a bouquet of pheromones to attract a mate or male lizards fight to display their superior strength, these social behaviors are common in the reptile world and have a profound impact on the health of the individual.

For example, a recent study of rattlesnakes in Australia found that they recognize their relatives, even when they have been raised in isolation for more than 2 years. The findings suggest that these snakes, and potentially other reptiles, lead far richer social lives than previously thought.

In The Secret Social Lives of Reptiles, three leading reptile experts bring together a wave of new research and a synthesis of classic studies to detail the extensive, varied social lives of turtles, crocodilians, lizards and snakes. Enhanced with dozens of beautiful images, this book details the many ways in which these animals communicate and interact.

Exploratory Behavior

Informed behavioural assessment offers an underused window into reptile welfare. Many captive-bred reptiles exhibit behaviors that are not typical of their natural environment, which can be a signal of negative welfare conditions. For example, pacing or repetitive circling behavior, often observed in mammals, may be a sign of stress and anxiety. Alternatively, if a reptile has no cause to be agitated, it is likely to display calm, relaxed behavior.

Reptiles are chemosensory animals and respond to a wide variety of environmental stimuli such as scent trails from food or conspecifics. Identifying and quantifying these cues is challenging. Y-mazes are commonly used tools that allow researchers to decipher vertebrate chemosensory behavior across a variety of taxa. However, Y-mazes require careful design and planning to ensure that the focal animal is exposed only to the appropriate stimuli.

An ethogram was developed to record the behaviour of Blanding’s turtles (Tiliqua adelaidensis) during modified open field tests. The ethogram includes a number of behavioural parameters such as exploratory activity, surfacing, hiding and basking. Other behavioural characteristics that were excluded from the final analysis were retracting the head, climbing and investigating. These were deemed to be less reliable as they are associated with other behavioral traits such as startle response and boldness. The coding of the test videos was performed by three observers and inter-observer reliability was assessed using the percent agreement method.


Aggression, the act of attacking another for protection or a perceived threat, is common in reptiles. This behavior is thought to increase the overall fitness of an animal by displacing or eliminating weaker individuals and protecting the territory and food resources of a dominant individual.

Many reptiles display aggressive behaviors when handled by humans. However, most of these aggressions are not based on fear or anger; they are simply part of a reptile’s natural defensive instinct. The most common reason for a snake to show aggressive behavior is when it has been mishandled, or in the case of wild animals, displaced from its territory or resource. Aggressive behavior may also be a result of a territorial dispute or the desire to establish dominance in a group, such as is often observed in tortoises.

Many reptiles exhibit defensive behaviors to warn potential predators that they are not a threat. These defensive behaviors include hissing, tail waving and displaying a caudal autotomy (tail shedding). A snake can also rattle its head or coil into an S-shaped position to produce sounds that will signal the presence of a predator. Other defensive behaviors include blood spurting (symbolically striking), faking death displays best known in eastern hog-nosed snakes, or retraction into the shell (best observed in chelonians). Some snakes regurgitate when frightened or stressed; this is a way to prepare for a quick escape and may serve as a distraction for the predator. Some snakes empty musk glands located in the cloacal area to release a foul-smelling odor or taste that may repel predators.


Many reptiles, especially lizards, have a variety of self-defense strategies. A common defensive tactic is the hissing noise. This may sound like a rattlesnake, and is meant to scare away predators. Some lizards combine hissing with other methods to appear more dangerous, such as opening the frills around their necks, or inflating their bodies, which makes them look like spiked balloons. A horned lizard even shoots a stream of blood from the corner of its eyes to frighten a predator into backing off.

Panther chameleons, which are popular in the pet trade, can also change color to blend in with their surroundings and confuse predators. The horned toad lizard can inflate itself up to twice its normal size, making it harder for predators to bite or swallow. And a gecko, whose tail is often the first part of its body to be grabbed by a predator, can shed it and then continue to wriggle it, distracting the predator from the rest of the creature and possibly giving the gecko a chance to escape.

Some reptiles lash out when frightened, including biting or scratching people who handle them inappropriately. This behavior can be attributed to misidentification or mistaken identity, and the person who is handling the reptile should be aware that they could be hurt if they are not careful.