Snakes are often perceived as silent, stealthy creatures, their movements characterized by quiet slithering. This common assumption overlooks a fascinating aspect of their biology, as snakes indeed produce a diverse array of sounds beyond just a hiss or rattle. These reptiles have developed various methods to create noises that serve different purposes in their natural environments, adapting their physical structures to communicate effectively.
How Snakes Produce Sounds
Hissing is the most recognized snake sound, produced by forcibly expelling air. A snake pushes air from its lungs through a small opening in its throat called the glottis. Cartilage within the glottis vibrates as air passes, creating the sibilant noise. The snake controls the hiss’s intensity and duration by adjusting the force of air expulsion and the glottis’s shape.
The iconic rattling sound, primarily associated with rattlesnakes, involves specialized structures at their tail tips. A rattlesnake’s rattle consists of interlocking, hollow segments made of keratin. When the snake rapidly vibrates its tail, these segments strike each other, generating a distinct buzzing or rattling sound. Each time a rattlesnake sheds its skin, a new segment is added to the rattle’s base, increasing its size.
Snakes produce other noises through various physical actions. Some species, like saw-scaled vipers, create a rasping sound by rubbing specialized, rough scales together, a process known as stridulation. This involves moving in an S-shape, causing the textured scales to scrape. Certain snakes, such as the pine snake, possess a laryngeal septum, allowing them to produce a shriek or bellow.
Less frequent sounds include coughing, clicking, or whistling, sometimes caused by air expulsion through the cloacal vent, often described as “cloacal popping.” Some larger snakes, like king cobras, produce a low growl due to unique tracheal diverticula that act as resonating chambers. Non-rattlesnakes vibrating their tails against dry leaves or other surfaces can produce rustling or buzzing noises.
The Role of Snake Sounds
The sounds snakes produce primarily serve as warnings to potential threats, aiming to avoid direct confrontation. Hissing acts as a general defensive mechanism, signaling that the snake feels threatened and desires space. This auditory signal deters predators or intruders, encouraging them to back off before a strike becomes necessary.
The rattling of a rattlesnake is an effective aposematic signal, alerting other animals to its presence and potential danger. This distinct sound helps the snake conserve energy and venom by scaring away large animals like hooved predators. A rapid increase in rattling frequency as a threat approaches can create an auditory illusion, making the snake seem closer than it is.
Some non-venomous snakes may employ acoustic mimicry, producing sounds that imitate those of venomous species for defense. For example, bull snakes can modify their hiss to resemble a rattle, deterring predators. This deceptive strategy helps them avoid harm without possessing venom.
While not as vocal as many other animals, sounds play a limited role in communication between snakes. Some sounds might be involved in courtship or territorial displays, though chemical signals and body language are more common. The primary audience for most snake sounds remains external threats, as many frequencies are too high for other snakes to hear.