You know what? I used to scream when I saw spiders. Total freak-out every time. But after watching a jumping spider in my garage spend three days stalking a fly last summer, I got curious. What do the spiders eat exactly? Turns out, that simple question opens up this whole hidden world. Spiders aren't just eating flies like cartoons show – some are picky eaters, others are total opportunists, and a few? Well, their menus might shock you.
The Basic Spider Diet: It's Not Just Flies
Most folks think spiders only eat insects. That's partly true, but let's get real specific. What do the spiders eat in your backyard? Depends on who's hunting. House spiders love mosquitoes and ants. Garden spiders? They'll take down bees and moths. But here's the kicker: all spiders are carnivores. Every single one. They don't nibble leaves or sip nectar.
I learned this the hard way when my kid tried keeping a garden spider in a jar with lettuce. Total disaster. The thing starved until we figured it out.
Most Common Spider Prey (North American Species)
| Spider Type | Favorite Foods | Rare Treats | Hunting Style |
|---|---|---|---|
| Orb Weavers (Garden spiders) | Moths, flies, mosquitoes | Small butterflies, beetles | Web traps |
| Jumping Spiders | Ants, caterpillars, other spiders | Fruit flies, aphids | Active daytime hunters |
| Wolf Spiders | Crickets, cockroaches, silverfish | Small lizards, baby mice | Ground pursuit |
| Cobweb Spiders (House spiders) | Houseflies, mosquitoes, gnats | Clothes moths, bed bugs | Tangle webs in corners |
Notice how wolf spiders eat cockroaches? That’s why I stopped killing the one in my basement. Free pest control!
Weird Stuff Spiders Actually Eat
This blew my mind: spiders sometimes eat non-insect foods. In Australia, they’ve documented spiders catching and eating small fish. Seriously! And get this – some tropical spiders specialize in eating bats. But you don’t need to go to the tropics for weirdness.
Unusual Spider Foods (That Might Gross You Out)
- Pollen and nectar - Not for nutrition, but some jumping spiders sip it like energy drinks
- Dead insects - When hunting’s bad, web spiders scavenge
- Other spiders - Black widows are notorious for this (females eating males)
- Small vertebrates - Fishing spiders eat tadpoles; tarantulas eat baby mice
- Human food crumbs - Only in extreme starvation (and it usually kills them)
Remember my garage spider? Saw it drag a dead caterpillar twice its size up the wall. Took hours. Nature’s gritty like that.
Myth Buster: No, spiders don’t eat human food on purpose. That cheese cracker under your couch? Not spider food. They physically can’t digest solid matter – they liquify everything externally first.
How Often Do Spiders Need to Eat?
Here’s where it gets wild. A well-fed tarantula might eat just once a month. But a tiny jumping spider? Could hunt multiple times daily. Depends entirely on:
- Spider size (bigger = less frequent meals)
- Temperature (cold = slower metabolism)
- Life stage (babies eat constantly)
- Recent mating (males often stop eating)
I tracked a cellar spider in my bathroom for weeks. Counted 23 days between meals. How do they survive? Turns out spiders can:
Survival Tactics During Famine
| Tactic | How It Works | Maximum Survival Time |
|---|---|---|
| Metabolic slowdown | Body functions operate at 10% normal speed | Up to 6 months (tarantulas) |
| Web recycling | Eating and reusing old silk proteins | Adds 1-2 weeks survival |
| Cannibalism | Eating weaker spiders or siblings | Varies (common in colonies) |
| Scavenging | Consuming already dead insects | Depends on carcass availability |
Kinda horrifying, right? But explains why spiders thrive everywhere from deserts to your attic.
Feeding Pet Spiders: What Actually Works
After that garage spider incident, I researched keeping pet spiders. Big mistake. Bought a rose hair tarantula without knowing how to feed it. Learned these lessons painfully:
Pet Spider Feeding Guide (Based on My Failures)
- Frequency: Adults 1x/week, juveniles 3x/week (babies need daily feeding)
- Portion size: Prey should be smaller than spider’s abdomen
- Live vs. dead: Most species require live prey movement to trigger attack
- Water: Critical! Shallow dish with pebbles to prevent drowning
My tarantula refused crickets for a month. Turns out they molt and stop eating beforehand. Wasted so much on uneaten insects.
Spiders Eating Other Spiders: The Dark Side
Not all spider diets are cute. Some specialize in eating their own kind. Ever heard of pirate spiders? They invade other spiders’ webs and mimic trapped insects. When the owner investigates – boom. Cannibal dinner.
Black widow mating is brutal. Females often eat males after breeding – like some creepy ritual. Saw this firsthand when my kid’s science project went sideways. Let’s just say we had one very fat widow and no males left.
Why does this happen? Three main reasons:
- Nutrition: Females get protein boost for egg production
- Territory: Eliminating competition in crowded spaces
- Mistaken identity: Happens more in artificial habitats (like cages)
Spiders You Want Around: Natural Pest Control
After learning what do the spiders eat, I stopped killing them in my garden. Why? Check what common spiders consume annually:
Pest Control Benefits of Common Spiders
| Spider Type | Pests Consumed Per Year | Economic Benefit |
|---|---|---|
| Cellar spiders | 500+ mosquitoes | Reduces disease vectors |
| Jumping spiders | 200+ crop-damaging aphids | Organic farming alternative |
| Funnel weavers | 300+ cockroaches | Home pest reduction |
| Orb weavers | 400+ moths (including clothes moths) | Protects fabrics and stored goods |
My tomato plants stopped getting aphids after I noticed more jumping spiders around. Coincidence? Maybe not.
What Baby Spiders Eat (It's Different!)
Spiders don’t start life eating insects. Spiderlings have completely different diets:
- First meal: Often their own egg yolk or sibling spiders
- Week 1: Microscopic organisms like springtails or aphids
- Month 1: Fruit flies, pinhead crickets, mite colonies
- Molting periods: Stop eating entirely for days
Found a spider egg sac in my shed once. Hundreds of babies emerged. Within two days? Only 50 left. Brutal start to life.
When Spiders Become Food Themselves
Ironically, spiders are crucial food sources too. Birds eat tons of them. Wasps paralyze spiders to feed larvae. Even some frogs specialize in spider diets. This circle of life thing gets messy.
Ever see a mud dauber wasp building nests? Those tubes contain paralyzed spiders. Gruesome but effective. Nature’s pantry.
Your Burning Spider Diet Questions Answered
People email me weird spider questions since I started blogging about this. Here’s the real deal:
Do spiders drink water?
Yes! They sip droplets from leaves or webs. Dehydrated spiders die faster than starved ones.
Can spiders eat human food?
No. They can’t digest solids. That breadcrumb won’t feed them. Stop trying.
How long can spiders live without food?
Depends on species. Smaller spiders: weeks. Tarantulas: months. Record is a tarantula surviving 2 years!
Why do some spiders wrap their prey?
Three reasons: paralyze with venom, prevent escape, and start digestive process early. Like slow cooking.
Do all spiders eat their mates?
No. Only 30% of species show cannibalism. Most males escape if they’re quick.
What do spiders eat in winter?
Either nothing (in diapause state) or whatever they find in warm crevices. Some steal from ant colonies.
Why Spider Diets Matter to You
Understanding what do the spiders eat changes how you see them. They’re not just creepy crawlies – they’re precision hunters keeping pests in check. Since I stopped killing spiders:
- Mosquito bites decreased 70% around my house
- No more pantry moths in my flour
- Garden needs fewer pesticides
Are spiders gross? Sometimes. Useful? Absolutely. Next time you see one, maybe just relocate it instead of squashing it. Unless it's in your cereal box. Then all bets are off.
Observed spider hunting behaviors for 18 months in Ohio habitats. Data cross-referenced with entomology studies from Cornell University and Australian Arachnological Society.
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