Complete Guide To The Eastern Rat Snake

Eastern Rat Snake Notes

Are Eastern Rat Snakes Venomous or Non-Venomous?

• Eastern Rat Snakes are non-venomous North Carolina snakes.
• These reptiles are non-aggressive and have no interest in humans unless we provoke them.
• However, Eastern Rat Snakes in North Carolina can grow to truly impressive size. Like all animals, Eastern Rat Snakes will defend themselves if harassed. And an eight-foot long snake can make quite an impression in its own defense.
  • Their first line of defense is to warn off threats by vibrating their tails. This behavior both looks and sounds like the tail-rattling performed by venomous rattlesnakes (which are truly dangerous reptiles) and is especially intimidating when the Eastern Rat Snakes are resting in dry leaf litter, which amplifies the noise.
  • Their second line of defense is to release foul-smelling fluid onto their skin.
  • If the noxious smell proves ineffective at deterring threats, they transition to their third line of defense which is direct, physical, and painful. These snakes will bite—hard and repeatedly.
  • REMINDER: Even though these snakes are not venomous, you MUST seek immediate medical attention for any injury caused by wildlife without question.
  • The best approach (as always) is to observe these snakes from a distance. Give these snakes the respect they deserve.

Eastern Rat Snake Food and Feeding

• Eastern Rat Snakes are non-venomous, constrictor snakes.
  • They locate prey by sight or smell, then coil their long bodies around the prey, squeeze until the prey suffocates, and swallow it whole.
  • Eastern Rat Snakes can swallow prey much wider than themselves because their upper and lower jaws are connected only loosely, and the snakes’ bodies are flexible and can stretch.

Prey Choices of Eastern Rat Snakes

• Eastern Rat Snakes prey on mammals (especially rodents), birds (both eggs and nestlings), moles, voles, shrews, amphibians, and other reptiles.
  • Many birders dislike Eastern Rat Snakes because they feed on bird eggs and nestlings.
  • But a four-year study of 81 Eastern Rat Snake fecal pellets showed that, while birds appeared in the snakes’ diets May through August:
    • 64% of samples contained mammalian prey
    • 30% of samples contained avian prey
    • “occurrence of birds never exceeded that of mammals in any month.” (Weatherhead, Blouin-Davey, and Cavey 20023, https://doi.org/10.1674/0003-0031(2003)150[0275:SAPDPO]2.0.CO;2
  • Eastern Rat Snakes likely do humans a great service by controlling populations of rats and mice, which damage agriculture and transmit serious diseases to humans.
• Also, Eastern Rat Snakes are not the only predator of bird eggs and nestlings. In fact, in some cases, Eastern Rat Snakes can help birds avoid predation by their other enemies.
  • Eastern Rat Snakes shed their skins 3 to 5 times a year as they grow and leave the remnants scattered around the landscape, often in the crooks of tree branches.
  • Some bird species incorporate these shed snake skins into their nest material to deter non-reptile predators.
    • For example, in North Carolina, Southern Flying Squirrels (Glaucomys volans) prey on Great Crested Flycatchers (Myiarchus crinitus) eggs and nestlings. Great Crested Flycatchers sometimes use Eastern Rat Snake skins as nest material.
    • One study researched the effectiveness of snake skin in deterring nest predators. The researchers set up a total of 60 artificial Great Crested Flycatcher nests; 20 nests had one Eastern Rat Snake skin inside each nest, 20 had both an Eastern Rat Snake skin inside and displayed outside each nest, and the remaining 20 had no Eastern Rat Snake skins at all.
      • Five out of the 20 control nests (those with no snake skins at all) were predated.
      • None of the 40 experimental nests (those with either one or two Eastern Rat Snake skins) were predated (Medlin and Risch 2006, https://doi.org/10.1093/condor/108.4.963).