Rat snakes are a diverse group of non-venomous, constricting snakes with approximately 50 species found across the Northern Hemisphere in North America, Europe, and Asia. They have varied physical characteristics, ranging from black to yellow or brown, often with stripes or blotches that change as they mature. Rat snakes are medium to large in size, with most species measuring 3 to 5 feet long. However, some, such as the black rat snake, can reach up to 8 feet in length. Continue reading to learn about the largest rat snake ever recorded.
Rat Snakes
Most species of rat snakes are not venomous, and those that are venomous are not harmful to humans.
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Although some Old World rat snakes may be mildly venomous, their venom is not considered medically significant to humans, and the majority of rat snakes are non-venomous. Instead, rat snakes rely on constriction to subdue prey. During constriction, a snake coils its muscular body around its prey, applying intense pressure to stop blood flow and cause rapid death.
Rat snakes have excellent climbing skills that allow them to navigate trees and buildings. These snakes will vibrate their tails rapidly against dry leaves or grass to create a rattling sound that mimics a venomous rattlesnake, a defensive behavior to deter predators. They can also release a foul-smelling musk as a defense mechanism.
Rat snakes are diurnal, hunting primarily during the day. In colder months, they enter a state of deep sleep called brumation, similar to hibernation in mammals, to conserve energy.
Size
The average rat snake measures from four to six feet. However, some species exceed this length.
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Newly hatched rat snakes are typically between 11 and 14.5 inches long, while most adult rat snakes measure between 3 and 5 feet long. Many species can grow longer, with some exceeding 6 feet. Rat snake size is not uniform and varies by species and region.
In many rat snake species, males are larger than females, which is unusual, as most snakes exhibit female-biased sexual size dimorphism, meaning females are typically larger to produce more or bigger offspring, increasing their survival chances.
This size difference in rat snakes is linked to male-to-male combat during the mating season. Larger males have an advantage in these wrestling matches, which increases their chances of securing a mate.
The Largest Rat Snake Ever Recorded
The largest rat snake ever recorded was a 13-foot, 1-inch keeled rat snake.
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In 2015, Indraneil Das, a conservation biologist at Universiti Malaysia Sarawak, published his book Field Guide to the Reptiles of South-East Asia. In the tome, he documented a keeled rat snake (Ptyas carinata) specimen measuring 13 feet and 1 inch.
The average keeled rat snake measures between 4 feet and 9 feet long. They are recognized by the distinctive keel or ridge on their scales, giving them a rugged appearance. This snake is an active hunter, feeding on rodents, frogs, and lizards. Despite its intimidating size and defensive behaviors, such as hissing and striking, the keeled rat snake is harmless to humans. It is a non-venomous constrictor that relies on its strength to subdue prey and defend itself.
