Are Daddy Long-legs Spiders? Understanding This Common Creature
You've probably spotted them in a garage corner or along a basement wall, those long-legged, spindly creatures that seem to hover in place. Most people call them daddy long-legs. Whether they're spiders at all depends entirely on which of three different animals you're looking at.
That distinction matters more than it might seem. Different creatures respond to different conditions, attract them in different ways, and call for different responses. Knowing what you're dealing with saves time, effort, and a fair amount of unnecessary concern.
Three Creatures, One Confusing Name
Harvestmen Are Not Spiders
The animal most people picture when they say "daddy long-legs" is a harvestman. Harvestmen are arachnids, but not spiders. The simplest way to tell them apart: harvestmen have one oval body section where spiders have two. They spin no webs. They produce no venom. They eat small insects, decaying plant material, and occasionally fungus.
In Southern California, harvestmen show up outside more than indoors. You'll find them under rocks, in mulch beds, along shaded fence lines and retaining walls. When disturbed, they move in that distinctive rhythmic bobbing motion. They're completely harmless and not particularly interested in living inside your home. If you find one in your kitchen, it wandered in by accident.
Another creature that gets called a daddy long legs is the crane fly; a flying insect that looks like a giant mosquito. It's not an arachnid. It cannot bite you. Adult crane flies live only a few days and are not a pest in any practical sense. If one ends up in your house, it'll find its way back out.
Cellar Spiders Are the Real Spiders
The one you're most likely encountering inside is a cellar spider. These are actual spiders in every sense: two distinct body segments, eight eyes, silk production, and venom. They build loose, irregular webs in corners, and once they find a location they like, they tend to stay there. You can vacuum the web down and find a new one in the same spot within days.
Cellar spiders are effective hunters. They catch and eat other insects that wander into their webs, including other spider species. A cellar spider taking down a black widow is not unusual. They're more capable than they look.
They also don't bother people. We've been in homes with significant cellar spider populations and have never seen one behave aggressively. They're not hunting you. They're waiting for something small and slow to stumble into their web.
One thing worth knowing: cellar spiders recycle their webs rather than abandoning them. An old web gets incorporated into the new one. That's why cellar spider webs look messier and more layered than the clean orb webs you'd see from a garden spider. If you're pulling down webs and finding dense, cottony accumulation in the same corners, that's what you're seeing.
Where Cellar Spiders Show Up
Cellar spiders need low light, humidity, and reliable insect traffic. In San Gabriel Valley and Inland Empire homes, that usually means:
Garage ceiling corners and wall joints
Crawl spaces and subfloor areas
Utility and laundry rooms
Dark storage closets with low foot traffic
Crane Fly
The third creature sharing this name is the crane fly, which isn't even an arachnid. It's actually a flying insect that looks like a giant mosquito with impossibly long legs.
Are Daddy Long Legs Dangerous?
The short answer is no. But because a specific myth about them circulates constantly, it's worth being direct.
The Venom Myth, Explained
You've probably heard some version of this: "daddy long legs are the most venomous spider, but their fangs are too small to bite you." Neither part is true. Harvestmen have no venom at all. Cellar spiders do produce venom, but it's calibrated for immobilizing flies and small insects. There's no toxicological evidence it poses any meaningful risk to people or pets, regardless of fang size.
Cellar spiders also rarely bite. They're not aggressive, and the only circumstance where a bite happens is when one gets physically pressed against skin. Most people who do get bitten feel nothing. The myth has been around long enough that it seems credible, but it doesn't hold up. For context on spiders that actually do pose a risk in Southern California, see our guide to brown recluses and other dangerous spiders. Cellar spiders don't belong in that category.
That said, "harmless" and "something you want sharing your space" are different things. A crawl space or garage with heavy web accumulation is a real problem even if the spiders themselves are benign. And a large cellar spider population is often a sign that some other insect is drawing them in. That underlying issue is usually worth finding.
When to Call Us About Spiders
For most homes, cellar spiders don't need professional treatment. Regular web removal, reducing moisture in affected areas, and sealing gaps around your foundation and utility entries handles the problem in most situations. Spider traps can also help reduce activity in specific problem areas. Cellar spiders don't reproduce as quickly as some pest species, and removing their webs consistently discourages them from staying.
Signs Worth a Call
A few situations are worth reaching out about:
Webs rebuild quickly after removal, which usually points to a larger insect population sustaining them
You're also seeing other spider species, particularly if you've spotted dangerous spiders like black widows in the same areas
The population is inside living areas, not just storage space
You have a moisture issue in the home that other fixes haven't resolved
We treat for both the spiders and the insects that draw them in. For more on the difference between normal seasonal spider activity and a real infestation, our post on spider infestations in Southern California breaks down what to watch for. If you're not sure what you're seeing is even a spider, our tick vs. spider guide covers the most common mix-ups.
Get a Free Estimate
If spiders are showing up somewhere you actually use – not just a storage corner – give us a call. We'll come out, take a look, and tell you honestly whether treatment makes sense. (626) 681-4120
We serve homeowners throughout the San Gabriel Valley and Inland Empire, including:
