Snakes are diverse, legless carnivores found globally, exhibiting a wide array of specialized diets. Locusts, a type of grasshopper known for swarming, are abundant insect biomass in many terrestrial ecosystems. Whether these reptiles consume this common invertebrate depends on the energetic demands and evolutionary specializations of different snake species. This requires looking at typical prey size, digestive limitations, and specific exceptions.
Are Locusts a Typical Prey Item for Snakes?
For the vast majority of snake species, especially those that reach moderate to large adult sizes, insects like locusts are not a regular component of their diet. Snakes are ambush predators that conserve energy by consuming large, infrequent meals. A mature snake, such as a rat snake or a python, requires the high caloric density provided by vertebrates like rodents, birds, or amphibians. The energy expended to locate, capture, and digest a small prey item like a locust often outweighs the minimal nutritional return. Consuming many small insects is inefficient compared to the substantial payoff of a single large prey item. While a large snake might opportunistically ingest a locust, it does not actively hunt them or rely on them for sustenance.
Specialized Snakes That Prey on Insects
While most large snakes ignore small invertebrates, a specialized group of smaller snakes relies on insects, including locusts and grasshoppers, as a significant part of their diet. The Smooth Green Snake (Opheodrys vernalis) is highly insectivorous, relying almost entirely on soft-bodied arthropods like crickets and caterpillars. The small Ringneck Snake (Diadophis punctatus) and various Brown Snakes often consume earthworms, slugs, and other invertebrates found under leaf litter. Some species, such as the Common Garter Snake (Thamnophis sirtalis), are dietary generalists that readily consume grasshoppers when abundant. Insects also play an important role in the early development of many species. Juvenile snakes that will eventually consume rodents often begin by feeding on small, easily captured invertebrates like crickets and grasshoppers, undergoing a distinct shift in diet as they mature.
Biological Reasons for Dietary Limitations
Most adult snakes avoid locusts due to a combination of metabolic and physical constraints. Metabolically, insects possess a lower overall caloric density compared to vertebrates because of their high water content. A large snake would need to consume an impractical quantity of locusts to equal the energy provided by a single small rodent, making the hunt energetically unsound. The second major limitation is the presence of chitin, the tough, structural polysaccharide forming the exoskeleton of locusts and other arthropods. While specialized insectivorous snakes have adapted digestive enzymes to break down chitin, it presents a challenge for species that primarily consume soft-bodied vertebrates. The indigestible nature of the hard outer shell means a portion of the meal passes through the digestive tract as waste, further reducing the nutritional benefit.