Buzz
Think spiders only devour insects? Think again. Over the years, researchers have uncovered that small animals and other unexpected food sources are key elements of many spiders’ diets.
1. Fish
arachne.org
Semiaquatic spiders like Dolomedes facetus (pictured above) have been known to hunt and consume small fish, as revealed in a recent study published in PLoS One. The researchers documented over 80 such instances across all continents except Antarctica, where these spiders ambush fish from the edges of ponds, lakes, rivers, and swamps. Using their neurotoxic venom, they paralyze the fish and then drag them to dry land to feast. The fish are typically small—ranging from one to 2.5 inches—but are, on average, 2.2 times larger than the spider.
One fascinating species, Argyroneta aquatica, builds a dome-shaped web amidst water plants, filling it with air from the surface. After catching its aquatic prey, the spider brings it back to the dome to enjoy its meal.
2. Bats
Researchers have documented over 52 instances of spiders preying on small or juvenile bats with wingspans reaching up to nine inches. In most of these cases, the bats get accidentally trapped in webs—typically those of tropical and subtropical orb-weaving spiders, whose webs can span six feet or more. However, some tarantula species have been known to actively hunt and ambush bats on rare occasions.
3. Birds
Spiders are not typically adapted to hunt birds. In fact, a bird colliding with a spider's web can cause considerable damage. But when life gives you challenges, turn them into opportunities: wrap them in silk, liquefy their insides, and enjoy the feast.
A 2012 study documented 69 instances of birds getting trapped in spider webs, including 18 cases where they were mummified in silk for the spiders’ consumption. (In many cases, humans intervened to rescue the birds.) The largest bird recorded was a three-ounce Laughing Dove, while most of the other trapped birds were hummingbirds. Orb weaver spiders were almost always responsible for these captures.
4. Snakes
Dinesh Rao/Flickr
Yes, you read that correctly—spiders can consume snakes. Don’t believe it? Check out this shocking video or these images. In 1926, Canadian entomologist James Henry Emerton wrote a vivid account of how the tarantula Grammostola actaeon captures and kills its snake prey:
When a Grammostola spider and a young snake are placed in the same cage, the spider attempts to capture the snake by targeting its head, clinging on despite the snake’s efforts to escape. After a minute or two, the spider's venom takes hold, and the snake becomes immobilized. The spider then begins at the head, using its mandibles to crush the snake, feeding on its soft tissue, sometimes taking over 24 hours to consume the entire animal, leaving only a formless mass behind.
5. Plants
R. L. Curry
Out of the world's 35,000 or so spider species, only one is known to eat plants. The mostly herbivorous Bagheera kiplingi feeds on the leaf tips of the acacia shrub found in Mexico and Central America. It uses its hunting abilities to evade the ants that inhabit the acacia, and occasionally supplements its diet by feeding on their larvae.
