10/18/2026
When a rattlesnake picks up the scent of a kingsnake, it does something it does for no other predator in North America: it goes completely quiet.
A rattlesnake will buzz its tail at coyotes, foxes, hawks, horses, and hikers. The rattle is its primary warning system, built to keep heavy animals from stepping on it and to make predators think twice about taking a bite full of tissue-destroying venom. Against a kingsnake, the rattlesnake ditches that strategy altogether. Instead, it tucks its head low and hoists the middle of its body off the dirt in a high horizontal arch known as a body bridge, using its midsection like a club to swat at the attacker and make itself look too wide to swallow.
According to researchers at the Arizona-Sonora Desert Museum, who have watched the routine play out repeatedly, it rarely works on a hungry kingsnake.
Once the kingsnake closes the distance, it clamps its jaws directly behind the rattlesnake’s head and throws its body into coils. In a 2017 study published in the *Journal of Experimental Biology*, researchers David Penning and Brad Moon tested the mechanics of that grip across 182 snakes by feeding them dead mice rigged with internal pressure sensors.
They found that kingsnakes squeeze at an average of 180 millimeters of mercury, well above the upper threshold of normal human blood pressure. That level of compression does not just suffocate prey; it physically stops the heart from pumping and shuts down the circulatory system in seconds. Sometimes the kingsnake starts swallowing the rattlesnake headfirst before it has even finished dying.
The rattlesnake's primary weapons do nothing to stop it. Kingsnakes carry blood proteins that neutralize the hemorrhaging toxins in pit viper venom. A rattlesnake strike that would drop a coyote or put a human in the intensive care unit barely registers on a kingsnake. It takes the fangs right into its scales and keeps tightening the coils.
Size does not save the rattlesnake, either. Penning noted that kingsnakes routinely hunt down and swallow snakes up to 20 percent longer than themselves, folding the extra length inside their own stomachs like an accordion. When his team paired smaller kingsnakes against larger rat snakes in the lab, the kingsnakes attacked immediately.
When Penning and Moon dissected and measured the trunk muscles of kingsnakes and rat snakes, they found the two species had virtually identical muscle mass and raw pulling strength. The difference came down entirely to wrapping geometry. During constriction tests, 91 percent of the kingsnakes wound their bodies into a neat, uniform coil that looked like a tight spring, applying crushing force evenly down the prey's spine with zero gaps. Only 5 percent of rat snakes managed a similar wrap.
Beyond rattlesnakes, kingsnakes regularly eat copperheads, cottonmouths, coral snakes, rat snakes, and even other kingsnakes. When they vanish from a landscape, the local venomous snake numbers can shift. A 2014 study in the journal *Herpetologica* by Christopher McClure and his colleagues analyzed trapping data across the southeastern United States, logging 299 kingsnakes and 2,012 copperheads across 377 traps. Even after accounting for habitat differences, the sites with the fewest kingsnakes consistently held the highest numbers of copperheads.
Georgia state herpetologist John Jensen noted that while more field work is needed to prove a direct cause-and-effect link, the pattern on the ground is hard to miss.
A rattlesnake will stand its ground and buzz at a 600-pound grizzly bear. When it smells a four-foot kingsnake coming through the brush, its only move is to keep quiet and hope it isn't found.
Image is for illustration purposes only.
Source: Penning & Moon (2017), Journal of Experimental Biology / National Geographic (2017) / Arizona-Sonora Desert Museum / McClure et al. (2014), Herpetologica / Atlanta Journal-Constitution (2014).
