The copperhead is a venomous pit viper found throughout the eastern and central United States, recognized by its distinctively patterned, reddish-brown body. Cicadas are large insects with a life cycle that includes both annual and periodical emergences, with massive, synchronized appearances of broods every 13 or 17 years. Copperheads actively seek out cicadas during these emergence events, making the insects a temporary, yet significant, part of their diet.
The Ecological Connection: Do Copperheads Eat Cicadas?
Copperheads are opportunistic predators that readily consume cicadas, especially during the large-scale emergence of periodical broods. This feeding behavior is a well-documented ecological phenomenon, particularly noticeable when billions of insects leave the ground simultaneously. The snakes temporarily shift their foraging focus to take advantage of this predictable, abundant food source.
During the emergence, copperheads alter their typical ambush-hunting strategy to actively pursue the insects, often moving away from their usual wooded cover. They congregate in areas where cicada nymphs are crawling out of the soil or climbing up vertical structures to molt.
Why Cicadas Are an Appealing Food Source
Cicadas represent a high-reward, low-effort meal. When the insects first emerge, they are soft-bodied and defenseless, offering the snake a meal that requires minimal energy expenditure for capture. Herpetologists often describe this as the snake equivalent of “fast food” because of its convenience and nutritional density.
The insects provide a substantial boost of energy and protein that supports the snakes’ overall health and reproductive success. Cicadas contain a high percentage of crude protein, often over 21 grams per 100 grams of insect. This nutrient spike is particularly beneficial for female copperheads, who use the extra resources to improve their body condition and the likelihood of successful reproduction. Snakes target the newly molted cicada nymphs, as these “soft-shelled” forms lack the hard, difficult-to-digest exoskeleton of the adult insects.
Increased Human-Copperhead Encounters
The copperhead’s temporary dietary focus on cicadas leads to an increased risk of human encounters in residential areas. As cicada nymphs emerge, they immediately climb the nearest vertical structure, such as tree trunks, bushes, or fence posts in suburban yards. The snakes follow this predictable food trail.
Copperheads are naturally nocturnal during warm weather and lurk around the bases of these cicada “hotspots” during the evening and nighttime hours. Since the snakes are active in residential spaces and focused on foraging, people walking near wood piles or under large trees at night are more likely to inadvertently step near a snake. This temporary overlap in activity and location is the primary driver of the surge in sightings and defensive bites during a cicada emergence year.