What Do Spiders Eat?

Spiders are found all around the world, except in Antarctica. There are over 50,000 species that belong to 136 families. Spiders aren’t insects, even though both spiders and insects belong to the Arthropoda phylum. They are arachnids, which means they have four pairs of legs, lack wings and antennae, and have two body segments instead of three.

The spider’s abdomen possesses spinnerets that produce silk, even though not all spiders spin webs. Like insects, spiders have jaws, but the jaws of most spiders have fangs. Those fangs deliver venom. Most spider venom isn’t dangerous to humans, but it can paralyze prey and initiate the spider’s digestion process. Read on to learn what spiders eat.

What Foods Do Spiders Eat?

First, not all spiders are strict carnivores. The beautiful green, gold, and red striped Bagheera kiplingi of Central America eats a mostly herbivorous diet. It eats structures called Beltian bodies that are found on the tips of acacia tree leaves. Though Bagheera kiplingi was described in 1896, scientists still don’t know how it eats Beltian bodies, which are rich in proteins and fat. These spiders also eat nectar and ant larvae, and if they’re really hungry, they’ll eat each other.

Most spiders are known to eat insects, but others eat nectar, seeds, pollen, honeydew, leaf material, silk from their webs, and dead arthropods. There’s a surprising variety of animals that spiders prey on. These prey are not all hapless creatures.

While there is some variation by species, spiders may consume the following:

• Insects such as mosquitoes, moths, cockroaches, and flies.
• Centipedes
• Mites
• Other arachnids
• Worms
• Snails
• Snakes
• Amphibians
• Small lizards
• Small birds
• Small bats
• Small fish
• Bird eggs

Of course, lizards and other vertebrates are taken by large spiders, but not very often. Even the largest spider in the world by mass, the Goliath bird-eating spider, rarely eats birds. Its usual diet consists of worms and larger insects, frogs, toads, snakes, and lizards.

Females of some spider species indeed eat the male after mating. Males sometimes avoid this fate by offering the female a fly or other prey to eat while he mates with her.

How Do Spiders Hunt Prey?

Spiders have a variety of hunting methods to catch prey. Some spin webs and wait for the food to fall into their traps, and some actively hunt.

Web Spinning Spiders

Many spiders spin webs to catch their prey. The prey, usually an insect, bumbles into the web, and the spider bites it, then wraps it in silk. It might start to eat the prey immediately, or cache it for later.

The diving bell spider (Argyroneta aquatica) spends nearly its entire life underwater and constructs a web shaped like a diving bell, which it fills with air and lives inside. When prey brushes against the bell or its anchoring threads, the spider snatches it. In contrast, fishing spiders (family Pisauridae) hunt on the water’s surface but do not build diving bell webs or live underwater.

Other spiders weave tiny webs, which they use as nets. They hold the webs in their first pair of legs and catch their prey in them. Some species release the web when prey enters it, while others hold on to the web to trap their prey.

Adult female spiders belonging to the Mastophora genus make bolas. They create a line of silk with a blob of sticky silk at one end to catch moths. Not only this, but the silk smells like moth pheromones. The males and Mastophora spiderlings simply mimic the pheromones and grab the moth with their front legs.

Hunters and Ambush Predators

Other spiders use a trapdoor strategy. They live in burrows and construct trapdoors attached to silk threads. When prey walks over these threads, the spider is alerted, shoots out, and grabs the prey.

Wolf spiders and jumping spiders actually hunt down their prey. These spiders have excellent vision, and wolf spiders in particular are colored to match their environment. It can be very hard to see a brown and tan wolf spider against a sandy background. Some can even lure prey out of hiding.

Some spiders have even evolved to mimic their prey. Ant-mimicking jumping spiders look and behave very much like ants, allowing them to infiltrate nests and grab either ants or the aphids they farm. Interestingly, scientists believe that ant mimicry developed to protect the spider from predators that eat spiders.

When a jumping spider finds potential prey, it might stalk it for a while, then orient itself, lay down a drag line, and leap.

Crab spiders wait on flowers to ambush their prey. They can even change their color to match that of the flower. Crab spider venom is potent, allowing it to successfully catch animals much bigger than itself.

What Animals Eat Spiders?

For creatures that are not sensitive to its venom, the spider is a sought-after part of their diets. Even humans eat spiders. The Goliath bird-eating spider is eaten after its irritating hairs are singed off. It is wrapped in banana leaves and roasted and is said to taste like shrimp. Other spiders eaten by humans include the Thai black spider and the golden orb-weaving spider, which is said to taste like foie gras. Other animals that eat spiders are:

• Insectivorous birds such as sparrows and bluebirds
• Lizards
• Tarantula hawk larvae
• Centipedes
• Other spiders
• Scorpions
• Monkeys
• Ticks
• Insects such as praying mantises
• Amphibians