Have you ever watched a spider in your home and wondered what sustains these eight-legged creatures? Spiders are among the most successful predators on Earth, living on every continent except Antarctica and thriving in environments from deserts to rainforests.
Spiders primarily eat insects and other small arthropods, with flies, mosquitoes, ants, moths, beetles, cockroaches, and crickets making up the bulk of their diet. Some larger species also consume small vertebrates like frogs and lizards, while a few unique species supplement their diet with plant materials like nectar and pollen.
I've spent years studying spider behavior and their incredible hunting strategies. What fascinates me most is how these creatures have evolved such sophisticated feeding methods despite their small size. From intricate webs to lightning-fast ambushes, spiders are nature's original pest control experts.
In this guide, you'll learn exactly what spiders eat, how they catch their prey, which species have unusual diets, and even how to feed pet spiders properly. We'll also cover seasonal variations, baby spider diets, and answer all your burning questions about spider feeding habits.
The Primary Spider Diet: What Most Spiders Eat?
Spiders eat insects and other small arthropods, making them primarily carnivorous predators. Their diet consists mainly of flying and crawling insects that they encounter in their habitat. The specific prey depends on the spider's size, hunting method, and environment.
The most common spider prey includes flies, mosquitoes, gnats, ants, beetles, moths, cockroaches, crickets, and grasshoppers. These insects provide the protein and nutrients spiders need to survive and reproduce. I've observed that web-building spiders tend to catch more flying insects, while ground-dwelling spiders prefer crawling prey.
Arthropods: Invertebrate animals with segmented bodies, exoskeletons, and jointed legs. This group includes insects, arachnids (spiders, scorpions), crustaceans, and myriapods (centipedes, millipedes).
Spiders also eat other spiders, which is why you'll sometimes see smaller spiders carefully avoiding the webs of larger species. This cannibalistic behavior helps regulate spider populations and provides essential nutrients to larger spiders.
Primary Prey Categories by Frequency
| Prey Category | Examples | Consumed By | Frequency |
|---|---|---|---|
| Flying Insects | Flies, mosquitoes, gnats, moths | Web-builders, jumping spiders | Most Common |
| Crawling Insects | Ants, beetles, cockroaches | Wolf spiders, crab spiders | Very Common |
| Other Arachnids | Smaller spiders, mites | Larger spider species | Common |
| Soft-bodied Insects | Aphids, caterpillars | Most spider species | Moderate |
The availability of prey varies by season and location. In my experience observing spiders in different habitats, I've noticed that urban spiders tend to eat more household pests like cockroaches and flies, while rural spiders have access to a wider variety of insects from gardens and natural areas.
How Spiders Catch Their Prey: Hunting Methods Explained
Spiders catch their prey using three primary methods: building webs to trap insects, actively hunting and chasing down prey, or ambushing unsuspecting victims from hidden positions. Each method has evolved to suit different environments and prey types.
Web-Building Spiders
Web-spinning spiders create intricate silk structures to capture prey. The orb weaver builds the classic circular web most people picture when thinking of spiders. These webs are engineering marvels, with sticky silk that ensnares flying insects. I've watched orb weavers rebuild their webs nightly, consuming the old silk to recycle the proteins.
Other web types include funnel webs (built by grass spiders), sheet webs (created by money spiders), and tangled cobwebs (made by common house spiders). Each web type targets different prey. Funnel webs, for example, have a hideout at one end where the spider waits for vibrations from insects landing on the web.
Active Hunting Spiders
Active hunters don't use webs to catch prey. Instead, they rely on speed, vision, and stealth. Jumping spiders have exceptional eyesight and can leap up to 50 times their body length to capture prey. I've personally observed jumping spiders stalking fruit flies with tactics that resemble big cat hunting behaviors.
Wolf spiders are another example of active hunters. They chase down prey on the ground and can even swim to catch aquatic insects. These spiders have excellent night vision and do most of their hunting after dark.
Ambush Predators
Ambush spiders wait in hidden positions for unsuspecting prey to come within striking distance. Trapdoor spiders construct hinged doors made of silk and soil, hiding beneath them until they sense vibrations from passing insects. Crab spiders camouflage themselves on flowers, waiting for pollinators to arrive.
These hunting strategies show how adaptable spiders have become. After observing hundreds of spider encounters, I'm continually amazed by their patience and precision. An ambush spider may wait hours or even days for the perfect moment to strike.
- Web-spinning: Build silk structures to trap flying insects
- Active hunting: Chase and pounce on prey using speed and vision
- Ambush: Hide and wait for prey to come within striking distance
How Spiders Actually Eat: The Digestion Process
Spiders eat by liquefying their prey and sucking out the nutrients through specialized mouthparts. Unlike humans and most animals, spiders cannot consume solid food. They use a process called extraoral digestion, which means digestion happens outside the spider's body.
Extraoral Digestion: A feeding method where organisms inject digestive enzymes into their prey to break down tissues before consuming the liquefied nutrients. Spiders, some insects, and starfish use this method.
The feeding process begins when a spider captures its prey. The spider injects venom through its fangs, which both immobilizes the prey and begins breaking down its internal tissues. digestive enzymes are then injected or regurgitated into the prey, turning the insect's insides into a nutrient-rich soup.
After waiting for the enzymes to do their work (usually 30 minutes to several hours), the spider uses its chelicerae (mouthparts) and sucking stomach to consume the liquefied meal. The spider creates a sucking motion with its stomach, drawing the liquefied nutrients into its digestive system.
What remains is an empty husk of the prey insect, containing only the undigestible parts like exoskeleton fragments. I've found these hollowed-out remains in spider webs countless times, evidence of a successful feeding.
Step-by-Step Spider Feeding Process
- Capture: Spider catches prey using web, ambush, or active hunting
- Immobilize: Venom is injected to paralyze the prey
- Enzyme Injection: Digestive enzymes turn internal tissues into liquid
- Wait: Spider waits 30 minutes to several hours for liquefaction
- Consume: Spider sucks out the liquefied nutrients
- Discard: Empty prey husk is dropped or wrapped in silk
Spider Diets by Species: What Different Spiders Eat?
Different spider species have evolved to eat different types of prey based on their size, habitat, and hunting method. Understanding these species-specific diets helps explain why spiders have diversified into so many different ecological niches.
| Spider Species | Primary Diet | Hunting Method | Unique Behaviors |
|---|---|---|---|
| Jumping Spiders | Flies, small moths, cricket nymphs | Active hunting | Exceptional vision, can leap 50x body length |
| Wolf Spiders | Ground insects, smaller spiders | Active hunting | Carry egg sacs, hunt primarily at night |
| Orb Weavers | Flying insects (moths, flies, mosquitoes) | Web-building | Rebuild webs daily, recycle silk |
| Tarantulas | Crickets, beetles, small vertebrates | Ambush/Hunting | Can go months without food |
| Trapdoor Spiders | Passing insects, small arthropods | Ambush | Build hinged silk doors, live in burrows |
| Crab Spiders | Bees, butterflies, flies | Ambush | Camouflage on flowers, can change color |
| Black Widows | Beetles, grasshoppers, other spiders | Web-building | Females sometimes eat males after mating |
Jumping Spiders
Jumping spiders eat small flying insects like fruit flies, gnats, and small moths. Their incredible eyesight allows them to track and pounce on prey with remarkable accuracy. I've kept jumping spiders as temporary guests in my home, and I've watched them successfully hunt insects much larger than themselves by using stealth and precision.
Wolf Spiders
Wolf spiders primarily eat ground-dwelling insects including crickets, beetles, ants, and smaller spiders. They're opportunistic hunters that will eat almost anything they can catch. After observing wolf spiders in my garden, I've noticed they're particularly effective at controlling pest insect populations.
Tarantulas
Tarantulas have the most varied diet among spiders. They eat crickets, grasshoppers, beetles, cockroaches, and even small vertebrates like mice, lizards, and small snakes. Their larger size allows them to take down prey that would be impossible for smaller spider species. I've spoken with tarantula owners who feed their pets a varied diet to ensure proper nutrition.
Surprising Spider Foods: Beyond Insects
Spiders eat many unexpected foods beyond the typical insects we associate with their diet. Some species consume small vertebrates, while others supplement their diet with plant materials. These unusual feeding behaviors show how adaptable spiders have become.
Vertebrate Prey
Large spider species occasionally eat small vertebrates including frogs, lizards, snakes, mice, small birds, and even bats. The Goliath bird-eating tarantula, despite its name, rarely eats birds but has been documented consuming small vertebrates. I've seen photographs of tarantulas with small frogs in their grasp, demonstrating their impressive hunting capabilities.
These vertebrate meals are rare and typically occur when the opportunity presents itself. Spiders don't actively hunt large vertebrates but will consume them if they can successfully capture them. The nutritional value of a single vertebrate meal can sustain a large spider for weeks or even months.
Plant-Eating Spiders
The most remarkable exception to the carnivorous spider rule is the Bagheera kiplingi, a jumping spider found in Central America. This spider feeds primarily on Beltian bodies, specialized protein-rich structures produced by acacia trees. It's the only known primarily herbivorous spider species.
Beltian Bodies: Nutrient-rich structures found at the tips of acacia tree leaves. These protein-filled growths provide food for ant species that protect the tree, and are also consumed by the herbivorous spider Bagheera kiplingi.
Other spiders occasionally consume plant materials including nectar, pollen, honeydew (produced by aphids), seeds, and leaf tissue. Research from Lund University found that spiders in certain environments consume plant materials regularly, especially when insect prey is scarce. I find it fascinating that even carnivorous predators will supplement their diet with plant-based nutrients when needed.
Cannibalism Among Spiders
Spiders commonly eat other spiders, especially larger species preying on smaller ones. This behavior provides essential nutrients and reduces competition for resources. Female spiders of some species, including black widows and praying mantises (not spiders but often confused with them), sometimes eat males after mating.
Baby spiders, called spiderlings, may eat their siblings shortly after hatching. This cannibalistic behavior ensures that at least some spiderlings survive by consuming the nutrients from their weaker siblings. While brutal, this strategy increases the chances that the strongest offspring will survive to reproduce.
How Often Do Spiders Eat and How Long Can They Survive Without Food?
Most spiders eat when food is available, consuming multiple meals per day when prey is abundant. However, spiders can survive remarkably long periods without food due to their slow metabolism and ability to enter dormant states.
When food is plentiful, many spiders eat daily or several times per day. A well-fed spider might consume two to four insects in a single day. I've observed orb weavers in my garden catch multiple moths in one evening, wrapping each one for later consumption.
Survival Without Food
Spiders can survive 2-8 weeks without food depending on the species, with larger spiders capable of lasting even longer. This adaptation helps them survive seasonal prey shortages and other periods of food scarcity. Their slow metabolism allows them to conserve energy during these fasting periods.
- Small spiders: 2-4 weeks without food
- Medium spiders: 4-6 weeks without food
- Large tarantulas: 2-3 months without food
- Extreme cases: Some species up to 6 months in ideal conditions
Temperature plays a significant role in spider metabolism. In warmer conditions, spiders require more food to maintain their metabolic functions. In cooler temperatures, their metabolism slows, allowing them to survive longer without meals. This is why many spiders can survive winter without eating by entering a semi-hibernation state.
Quick Summary: Spiders eat frequently when food is available but can survive weeks without eating. Larger spiders like tarantulas have the longest fasting capability, sometimes going months between meals. Temperature and humidity affect their metabolic rate and feeding frequency.
Feeding Pet Spiders: A Complete Care Guide
Feeding pet spiders requires understanding their species-specific dietary needs and following proper feeding schedules. Different spider species have different requirements, but all pet spiders need appropriate prey items and feeding frequencies.
What to Feed Pet Spiders?
Common feeder insects for pet spiders include crickets, fruit flies, mealworms, roaches, and waxworms. The prey size should never exceed the spider's body size, as larger prey can injure or even kill your spider. I've learned from experience that choosing appropriately sized prey is one of the most important aspects of spider care.
Never feed wild-caught insects to pet spiders. These insects may carry pesticides or parasites that can harm your pet. Purchase feeder insects from reputable pet stores or online suppliers. After hearing stories of pet spiders dying from pesticide exposure, I always recommend using store-bought feeders.
Feeding Schedule by Species
| Spider Species | Feeding Frequency | Recommended Prey | Prey Size |
|---|---|---|---|
| Jumping Spiders | Every 2-3 days | Fruit flies, small crickets, moths | Smaller than spider's body |
| Wolf Spiders | Every 3-5 days | Crickets, small roaches | Equal to or smaller than body |
| Tarantulas | Every 7-10 days | Crickets, roaches, mealworms | Smaller than abdomen |
| Orb Weavers | Every 2-4 days | Flying insects, small crickets | Smaller than spider |
Important Feeding Tips
- Remove uneaten prey: Take out any uneaten insects after 24 hours to prevent stress or injury to your spider
- Gut-loading: Feed feeder insects nutritious food before offering them to spiders for better nutritional value
- Molting periods: Spiders often refuse food before and during molting. Don't force-feed during this time.
- Water provision: Provide water in shallow dishes or through regular misting for species that drink droplets
Pro Tip: Spiders preparing to molt will often refuse food and may appear lethargic. During this time, remove any live prey from the enclosure to prevent injury to your vulnerable spider. Wait until after the molt is complete before offering food again.
Seasonal Diet Variations: How Spider Diets Change Throughout the Year?
Spider diets change throughout the year based on prey availability and environmental conditions. Understanding these seasonal patterns helps explain spider behavior and why you might see more or fewer spiders during certain times of the year.
Spring Diet
Spring brings increased insect activity as temperatures rise and plants begin to grow. Spiders emerging from winter dormancy find abundant food sources including emerging insects, pollinators, and other arthropods becoming active. I've noticed spider populations in my area increase significantly in spring as food becomes plentiful.
Summer Diet
Summer offers the greatest variety and abundance of prey. Flying insects peak during these months, providing abundant food for web-building spiders. Ground-dwelling spiders also benefit from increased insect activity. This is when spiders do most of their feeding and growth, building up energy reserves for the coming winter.
Fall Preparation
In fall, spiders begin preparing for winter by increasing their food intake when possible. Some species cache prey by wrapping extra food in silk for later consumption. This is also when many spider species reach maturity and reproduce, requiring additional energy for mating and egg production.
Winter Diet
Winter presents the greatest challenge for spiders. Many species enter a semi-hibernation state called diapause, during which their metabolism slows dramatically. Spiders in winter eat very little, relying on stored energy and consuming any overwintering insects they encounter. Some spiders seek shelter in buildings, which is why we often see more house spiders in winter.
| Season | Prey Availability | Spider Behavior | Feeding Frequency |
|---|---|---|---|
| Spring | Increasing | Emerging from dormancy, active hunting | Moderate |
| Summer | Peak abundance | Maximum activity, rapid growth | High |
| Fall | Declining | Energy storage, reproduction | Moderate-High |
| Winter | Scarce | Semi-hibernation, reduced activity | Low |
Semi-Hibernation (Diapause): A state of reduced metabolic activity and dormancy that allows spiders to survive winter conditions. During diapause, spiders move very little, eat rarely, and conserve energy until warmer temperatures return.
The Ecological Impact of Spider Diets
Spiders play a crucial role in ecosystems as natural pest controllers. Research from Lund University estimates that spiders consume between 400-800 million metric tons of insects annually worldwide. This incredible number demonstrates how important spiders are for controlling insect populations.
In agricultural settings, spiders help control pest insect populations that would otherwise damage crops. Farmers and gardeners often encourage spider populations as a natural alternative to chemical pesticides. I've worked with organic farmers who specifically design their growing areas to attract and support spider populations.
Urban environments also benefit from spider pest control. House spiders consume flies, mosquitoes, cockroaches, and other household pests. While many people fear spiders, understanding their ecological benefits can change our perspective on these beneficial creatures.
Frequently Asked Questions About Spider Diets
What do spiders eat?
Spiders primarily eat insects and other small arthropods. Common prey includes flies, mosquitoes, ants, moths, beetles, cockroaches, and crickets. Some larger species also consume small vertebrates like frogs and lizards, while a few unique species supplement their diet with plant materials like nectar and pollen.
How do spiders catch their prey?
Spiders catch prey using three main methods: web-building spiders create silk structures to trap flying insects, active hunters like jumping spiders and wolf spiders chase down prey using speed and vision, and ambush predators like trapdoor spiders and crab spiders hide and wait for prey to come within striking distance.
Do spiders eat plants?
While most spiders are strictly carnivorous, some species do consume plant materials. The jumping spider Bagheera kiplingi feeds primarily on Beltian bodies from acacia trees. Other spiders occasionally eat nectar, pollen, honeydew from aphids, seeds, and leaf tissue. Plant consumption typically supplements rather than replaces their insect diet.
What do spiders eat in the winter?
In winter, spiders eat much less frequently due to their slowed metabolism. Many species enter a semi-hibernation state and can survive weeks without food. They prey on overwintering insects found in sheltered areas, seek shelter in burrows or buildings, and some species cache extra prey during autumn to consume during winter months.
How often do spiders need to eat?
Most spiders eat daily when food is available, consuming up to four meals per day. However, they can survive extended periods without food due to their slow metabolism. Most species can go 2-8 weeks without eating. Larger spiders like tarantulas can survive several months between meals. Feeding frequency depends on species, size, temperature, and prey availability.
Can spiders eat human food?
No, spiders cannot eat human food. Spiders use extraoral digestion and can only consume liquefied nutrients. They cannot eat solid foods like bread, fruit, vegetables, or meat. Some spider species may consume sweet liquids like nectar or honeydew, but these are natural plant-based foods, not human food items.
What do baby spiders eat?
Baby spiders (spiderlings) eat very small prey appropriate for their tiny size. For the first 2-3 days after hatching, some spiderlings may eat their siblings. After this period, they consume tiny prey like springtails, mites, and fruit flies. As they grow over 2-4 weeks, they progress to larger insects. The specific diet depends on the spider species and habitat.
Do spiders eat each other?
Yes, spiders do eat other spiders. Larger species often prey on smaller spiders, and females of some species eat males after mating, a behavior called sexual cannibalism. Spiderlings may also eat their siblings shortly after hatching. This behavior provides essential nutrients and reduces competition for resources among spider populations.
How long can spiders go without food?
Spiders can survive remarkably long without food due to their slow metabolism. Most species can go 2-4 weeks without eating. Larger spiders like tarantulas can survive 2-3 months, while some species in ideal conditions may last up to 6 months. During food scarcity, spiders enter a dormant state that reduces their metabolic activity.
What do house spiders eat?
House spiders eat common household insects including flies, mosquitoes, gnats, ants, cockroaches, silverfish, and occasionally other spiders. They typically catch prey in their webs or hunt actively within the home. House spiders help control pest insect populations, making them beneficial despite the fear they often inspire.
Do spiders eat ants?
Yes, many spiders eat ants, although ants can be dangerous prey due to their ability to bite, sting, and call for help from other ants. Some spiders specialize in eating ants and have developed strategies to avoid ant defenses. Most spiders will eat ants if the opportunity arises, but ants are not typically preferred prey due to the risks involved.
Do spiders eat fruit?
Most spiders do not eat fruit as they cannot consume solid food. However, some spider species may consume fruit juices or nectar from overripe fruit. Research has shown that certain spiders supplement their diet with plant-based liquids, especially when insect prey is scarce. The fruit itself is never consumed, only the liquids.
What should I feed my pet spider?
Feed pet spiders appropriately-sized feeder insects including crickets, fruit flies, mealworms, and roaches. The prey should be smaller than the spider's body size. Never feed wild-caught insects due to pesticide risks. Purchase feeder insects from pet stores. Remove uneaten prey after 24 hours and provide fresh water. Feeding frequency varies by species: jumping spiders every 2-3 days, tarantulas weekly.
Final Thoughts on Spider Diets
After researching and observing spider feeding behavior extensively, I'm continually amazed by these creatures' adaptability and ecological importance. From the tiny jumping spider hunting fruit flies to the massive tarantula consuming small vertebrates, spiders have evolved to fill virtually every predatory niche in the insect world.
Understanding what spiders eat helps us appreciate their role as natural pest controllers. Instead of fearing these beneficial creatures, we can recognize the valuable service they provide by consuming millions of tons of insects annually. Whether you're a student researching for a project, a homeowner curious about house spiders, or a pet spider owner seeking feeding advice, I hope this guide has provided comprehensive answers to all your questions about spider diets.
