Spiders are a common presence in many ecosystems, known for their predatory role in controlling insect populations. However, spiders themselves are not exempt from the food chain and face natural threats from other creatures. This article explores the diverse array of animals that prey on spiders.
Invertebrate Predators of Spiders
Many specialized predators of spiders are found within the invertebrate world. Spider wasps paralyze spiders with a sting before dragging them to a burrow or nest chamber. The wasp then lays a single egg on the immobilized spider, which serves as food for the developing larva. These wasps often specialize in certain spider types, targeting wolf spiders, tarantulas, or jumping spiders.
Assassin bugs include spiders in their diet, employing stealth and a venomous proboscis to subdue prey. Some species tap spiders with their antennae to disorient them, allowing a fatal venomous strike. The venom paralyzes the spider and liquefies its internal organs for consumption. Praying mantises are generalist predators that readily consume spiders when encountered, using camouflage and rapid forelegs to ambush their prey.
Cannibalism, where one spider preys on another of the same species, also occurs. This can manifest as sexual cannibalism, where a female consumes a male during or after mating. Non-sexual cannibalism can also occur, driven by hunger or territorial aggression. Centipedes are invertebrate predators that actively hunt spiders. These multi-legged carnivores are nocturnal hunters that use ambushing or chasing tactics to capture their prey.
Avian Hunters
Birds frequently include spiders in their diverse diets, particularly many insectivorous species. Common garden birds such as wrens, chickadees, warblers, sparrows, and robins all opportunistically consume spiders. Spiders offer a valuable source of protein and essential nutrients for these birds, especially important during the demanding breeding season when feeding their young. Birds employ various strategies to find spiders, foraging on foliage, branches, or even plucking them directly from webs. Some species, like blue tits and great tits, are known to feed spiders to their chicks.
Reptiles, Amphibians, and Mammals as Spider Eaters
Reptiles, amphibians, and mammals also contribute to the natural predation of spiders across various ecosystems. Lizards are common predators of spiders. Smaller species like anoles and geckos frequently prey on spiders, including those found in and around human dwellings. Some lizards, such as southern alligator lizards, consume even venomous spiders like black widows.
Amphibians like frogs and toads readily consume spiders as part of their generalist diets. They typically use their sticky tongues to capture prey. The size of the amphibian often dictates the size of the spiders they can effectively prey upon. Frogs can safely eat venomous spiders because the venom is digested in their stomach.
Small mammals are also opportunistic spider eaters. Shrews, for instance, include spiders in their diet, alongside insects and slugs. These tiny mammals have high metabolic rates, requiring them to consume significant amounts of food daily. Certain bat species feed on spiders, particularly when other aerial insect prey is less abundant. Rodents, including mice and rats, are omnivores that consume spiders if encountered, although they typically prefer plant-based foods.