Worms serve as a fundamental food source for a diverse array of animals across many ecosystems. Earthworms, in particular, contribute to soil health by aerating and enriching it. Their widespread presence provides a consistent and accessible food supply for numerous predators, highlighting the interconnectedness of nature’s feeding relationships.
Familiar Worm-Eating Animals
American robins are well-known for their worm-hunting behavior, often seen hopping across lawns, stopping abruptly, and then pulling a worm from the soil. They primarily use visual cues to detect worms, often tilting their heads for a better look, and can also perceive subtle ground movements or vibrations.
Moles, adapted for a subterranean existence, rely heavily on earthworms. A single mole can consume up to 200 worms or about half its body weight daily. Moles create intricate tunnel systems, using their sensitive snouts and keen sense of smell to detect earthworms within these tunnels. They may even paralyze and store earthworms in underground chambers for later consumption, with some chambers containing up to 1,000 worms.
Shrews are voracious worm eaters. These active insectivores have high metabolic rates, needing to eat frequently and often consuming 80 to 90 percent of their body weight in food daily. Hedgehogs, primarily insectivores, also consider earthworms an important food source, providing protein and calcium. They forage through leaf litter and soil, using their excellent sense of smell to locate worms.
Unexpected Worm Eaters
Many species of fish readily consume aquatic worms and detritus worms found in their habitats. Bottom-feeding fish like Corydoras catfish and various loach species (e.g., clown loach, zebra loach) sift through substrate to find these worms. Others, like bettas, angelfish, trout, and catfish, will eat them as they float in the water column.
Amphibians like frogs and salamanders are opportunistic feeders that consume worms. Frogs have an appetite for worms, which provide protein and other nutrients. Reptiles, such as certain snake species and turtles, also prey on worms. The Eastern worm snake is named for its diet, and turtles consume worms as they forage in aquatic and terrestrial environments.
Even some larger mammals, not typically thought of as worm specialists, consume them. Raccoons and skunks, for example, dig through turf to find protein-rich worms and grubs. Possums, being opportunistic feeders, also include worms in their diverse diet, using their sharp teeth and keen sense of smell to locate them.
Worms as a Vital Food Source
Earthworms are a rich source of protein, ranging from approximately 54.6% to 76.82% on a dry matter basis. This high protein content makes them comparable to, and in some cases superior to, conventional protein sources like fish meal or soybean meal.
In addition to protein, earthworms provide fats (6-19% dry matter), carbohydrates (5-21% dry matter), and essential minerals such as iron, calcium, potassium, phosphorus, and magnesium. They also contain amino acids like lysine and methionine, crucial for the growth and development of many animals. Their robust nutritional profile and widespread presence establish worms as a reliable, calorie-dense food source across numerous food chains.