Frogs are insectivorous amphibians that primarily rely on a diet of invertebrates, consuming almost any prey item that fits into their mouth. As opportunistic predators, they respond to the availability of food in their immediate environment, which influences their diet composition throughout the year. This flexibility means that various insects, including beetles, flies, and spiders, regularly feature in their meals. Termites are a valuable food source, and their interaction with frogs is governed by specific biological adaptations and ecological circumstances.
Termites in the Frog Diet
Frogs consume termites, but these insects generally serve as a supplementary or secondary food source rather than a dietary staple. Consumption increases dramatically during swarming events, when winged reproductive termites, known as alates, emerge in massive numbers. This synchronous emergence creates an easily accessible, high-density food source that frogs exploit. Frogs often position themselves near the alates’ emergence points to gorge on the slow-moving, newly winged insects.
Termites are nutritionally beneficial, especially the winged forms, which are rich in protein and fat, providing a concentrated energy source. Studies show high protein content in winged termites, sometimes exceeding 35% of their dry mass, making them a quality meal for rapid fat and energy storage. This high caloric content is important for species that must quickly build up reserves for periods of dormancy or breeding. While worker and soldier castes are also eaten, the alates offer a superior nutritional reward.
The volume of termites available during a swarm allows a frog to consume a significant amount of food quickly, maximizing energy intake for minimal hunting effort. This is a common strategy for predators exploiting temporary resource spikes. For most species, however, termites are not a constant, primary food source due to their underground or concealed nature outside of these brief reproductive flights.
Predation Mechanics for Small, Numerous Prey
The frog’s success in capturing small, numerous prey like termites is due to a highly specialized, rapid predation mechanism centered on its tongue. The tongue is launched at the prey in a fraction of a second, often taking less than 0.07 seconds to complete the strike. This speed ensures the tiny insect has little time to react or escape.
The physical properties of the tongue are uniquely suited for this high-speed capture. The tissue is extremely soft, comparable to brain tissue, and viscoelastic, allowing it to deform and wrap completely around the small prey upon impact. This softness, combined with a specialized non-Newtonian saliva, creates an effective, high-adhesion system.
The saliva is shear-thinning, meaning its viscosity changes depending on the force applied. When the tongue hits the termite, the saliva temporarily thins to flow into every crevice of the insect’s exoskeleton. As the tongue retracts, the force changes, and the saliva instantly thickens to a consistency more viscous than honey, effectively locking the termite onto the tongue. This mechanism provides a grip strong enough to withstand forces up to 12 times that of gravity as the meal is pulled back into the mouth.
Habitat and Species Predisposed to Termite Consumption
The species most likely to consume termites are those that share the insects’ terrestrial or fossorial (burrowing) habitats. Frogs with specialized body shapes and behaviors are often termite specialists. Narrow-mouthed frogs (Microhylidae family) are classic examples, with many species adapted to feed almost exclusively on small social insects like ants and termites.
The Muller’s Termite Frog (Dermatonotus muelleri), a burrowing microhylid from South America, is one species whose diet consists largely of termites. These frogs are often found near termite mounds or colonies, emerging from the soil to feed on the concentrated population. Another group includes the Spadefoot Toads (Scaphiopus and Spea genera), which inhabit arid and semi-arid regions where termites are abundant.
Spadefoot toads use a hard, keratinous projection on their hind feet, the “spade,” to dig backwards into loose soil, placing them near subterranean termite colonies. They emerge following heavy rains, which often coincide with the termites’ swarming flights. These toads can consume as much as half of their body weight in invertebrates, including termites, in a single night of opportunistic feeding to quickly replenish energy reserves.