Spiders are integral components of diverse ecosystems, occupying a specific niche within food webs. Despite their predatory nature, these eight-legged arachnids are also a significant food source for many other animals. Many creatures actively hunt or opportunistically consume spiders, highlighting complex interdependencies. These predator-prey relationships offer insight into the ecological balance that governs spider populations.
Other Arthropod Predators
Many arthropods prey on spiders, often employing specialized hunting strategies. Spider wasps, for instance, paralyze a spider with a sting, then drag the immobilized arachnid to a burrow or nest. There, she lays an egg on it, and the hatching larva consumes the spider. Different spider wasp species specialize in preying on particular types of spiders, including tarantulas, wolf spiders, and jumping spiders.
Assassin bugs inject venom to liquefy a spider’s internal tissues before consumption. Praying mantises are generalist predators that capture and consume spiders. Centipedes, swift, nocturnal hunters, also feed on spiders. Their venomous claws can puncture a spider’s exoskeleton.
Spiders themselves are also significant predators of other spiders, a phenomenon known as cannibalism. Larger spider species, such as some wolf spiders, prey on smaller individuals, including their own kind. The cellar spider can subdue much larger spiders by wrapping them in silk from a safe distance.
Avian Predators
Birds are widespread predators of spiders, with many insectivorous species including arachnids in their diets. Common birds such as wrens, sparrows, robins, and bluebirds regularly consume spiders. These birds often forage among foliage or pluck spiders directly from their webs.
Spiders provide an important nutritional component for birds, particularly for their young. Spiders contain taurine, an amino acid beneficial for the development and behavior of young birds. Some species, like blue tits and great tits, feed spiders to their chicks. Even hummingbirds, primarily nectar feeders, occasionally consume spiders and the insects caught in their webs for essential nutrients.
Reptilian and Amphibian Predators
Reptiles and amphibians also contribute to the control of spider populations, often as part of their insectivorous diets. Various lizard species, including geckos and chameleons, are predators of spiders. The introduction of lizards to islands can significantly reduce spider populations, demonstrating their effectiveness as predators.
Frogs and toads are opportunistic feeders that consume spiders. They use their long, sticky tongues to capture small invertebrates. While spiders make up a small percentage of a toad’s diet, they are a common food source for many species.
Mammalian Predators
While less commonly associated with spider consumption, several smaller mammalian species include spiders in their diets. Shrews are insectivorous mammals that frequently prey on a variety of invertebrates, including spiders. Their high metabolism requires them to consume food regularly, making them effective foragers of small ground-dwelling creatures.
Mice, being omnivorous and opportunistic, will also eat spiders when available, though spiders are not typically their preferred food source. Given a choice, mice generally favor plant-based foods such as fruits, nuts, and seeds. Bats, primarily known for consuming flying insects, have also been observed eating spiders. While spiders do not constitute a significant portion of most bat diets, they are occasionally consumed, particularly if found in webs or on surfaces where bats can easily snatch them.