The Thorny Devil, Moloch horridus, is a small Australian lizard found across the arid and semi-arid deserts of Australia. This reptile is recognizable by the dense array of conical spines covering its body. Its appearance has earned it names such as the Mountain Devil and Thorny Dragon. This article examines the biology and behavior of this animal to determine if its intimidating façade poses a threat to human safety.
The Immediate Answer: Assessing the Threat
The Thorny Devil poses no danger to humans. They are non-venomous and have no offensive mechanisms that could injure a person. The lizard is docile and exhibits a temperament that favors defense and evasion over confrontation.
When faced with a perceived threat, the Thorny Devil’s primary response is to freeze completely or move with a slow, rocking gait to confuse predators. They are also known to inflate their bodies with air. This passive defense mechanism is intended to make them appear larger and more difficult for a predator to swallow.
Appearance Versus Reality
The perception of danger comes from the lizard’s morphology, which is built for defense against natural predators. The numerous sharp, cone-shaped spines covering its body are a physical deterrent. These spines are not used aggressively but serve the passive purpose of making the lizard an unappealing meal for birds of prey or goannas.
The Thorny Devil possesses a prominent, spiny knob of soft tissue on the back of its neck, often referred to as a “false head.” When threatened, the lizard tucks its real head down between its front legs and presents this decoy to an attacker. This adaptation diverts a potential predator’s strike away from the lizard’s actual head. Its skin exhibits cryptic coloration, a mottled mix of yellow, brown, and tan that changes with temperature to help it blend into the sandy desert environment.
Diet, Size, and Temperament
The lack of threat is solidified by the animal’s specialized diet and physical limitations. Thorny Devils are myrmecophagous; their diet consists almost exclusively of small black ants. They stand motionless over an ant trail and use a short, sticky tongue to lap up their prey, consuming hundreds, and sometimes up to 3,000 ants, in a single feeding session.
They are also small, typically reaching a total length of only 6 to 8.3 inches, including the tail. Their specialized, non-predatory diet, small stature, and slow movements confirm the Thorny Devil as a shy, harmless resident of the Australian desert.