Cellar spiders are one of the most common household spiders in Florida, showing up in corners, garages, sheds, and anywhere with a quiet, sheltered spot. They belong to the family Pholcidae and are often called “daddy longlegs spiders,” which causes no end of confusion with a completely different creature. They’re harmless to people and actually useful predators of household insects and even other spiders.
Identifying Cellar Spiders
Cellar spiders in Florida are typically from the genus Pholcus. They have a pale, almost translucent body with extremely long, thin legs that can make them look fragile. The key feature that separates them from similar-looking creatures is their two distinct body segments: a small front section (the head and thorax fused together) and a separate, elongated abdomen. They have eight eyes, produce silk, and build webs. If you see a long-legged spider hanging upside down in a messy, irregular web, you’re almost certainly looking at a cellar spider.
Florida’s warm, humid climate suits them well. You’ll find them in garages, bathrooms, closets, basements, attics, under eaves, and in sheds. They favor dark, undisturbed areas with enough moisture and insect traffic to keep them fed.
Cellar Spiders vs. Harvestmen
The “daddy longlegs” label gets applied to both cellar spiders and harvestmen (order Opiliones), but they’re very different animals. Harvestmen have a single rounded body because their two main body sections are fused together, giving them that oval, pill-like shape. They only have two eyes, produce no silk, build no webs, and have no venom at all. Cellar spiders, on the other hand, are true spiders with two separate body segments, eight eyes, spinnerets for making silk, and venom glands.
If it’s sitting in a web, it’s a cellar spider. Harvestmen wander freely and are typically found outdoors in leaf litter or on tree trunks.
The “Most Venomous Spider” Myth
You’ve probably heard the claim that daddy longlegs are the most venomous spiders in the world but their fangs are too short to bite humans. Both parts of this are wrong. No toxicological studies have ever tested pholcid venom on any mammalian system, so there’s simply no scientific basis for calling their venom especially dangerous. The idea is a persistent urban legend with no research behind it.
The fang part doesn’t hold up either. Cellar spiders do have short fangs with a structure called “uncate,” where a secondary tooth meets the fang like a pair of tongs. Brown recluse spiders have the same fang structure and can obviously bite humans. So the anatomy alone doesn’t prevent skin penetration. That said, there is no documented case of a cellar spider biting a person and causing any harmful reaction. They pose no medical concern.
What Cellar Spiders Eat
Cellar spiders are generalist predators that catch a variety of small insects in their webs, including mosquitoes, gnats, flies, and small moths. Their hunting method is distinctive: they hang upside down on their loose, messy web and wait for prey to blunder into the silk. Once something gets tangled, the spider vigorously shakes the entire web to wrap the prey further in silk before moving in to feed.
What makes cellar spiders particularly interesting is that they also hunt other spiders. They’ll invade the webs of other species, including larger and potentially more dangerous ones, and prey on them directly. In Florida homes, this means cellar spiders can help keep populations of other spider species in check. Some homeowners tolerate them for exactly this reason.
Why They Build Up in Florida Homes
Florida’s year-round warmth and humidity create ideal conditions for cellar spiders to breed continuously. Unlike cooler climates where spider activity drops in winter, Florida homes can see cellar spider populations grow steadily through all seasons. Each egg sac can contain hundreds of young spiders, and females carry their egg sacs in their jaws rather than attaching them to the web, so the eggs travel wherever the mother goes.
The spiders gravitate toward quiet, cluttered spaces. Garages stacked with boxes, closets that rarely get opened, storage areas under stairs, and attic spaces all provide exactly the kind of undisturbed environment they prefer. In Florida, screened porches and lanais are also common spots since they offer shelter while still attracting plenty of flying insects.
Keeping Cellar Spiders Out
The most effective approach is straightforward: regular cleaning. A vacuum cleaner or broom removes spiders, webs, and egg sacs in one pass. Destroying egg sacs is especially important since each one can release hundreds of spiderlings. Focus on corners, ceiling edges, closets, garages, and any other spots that tend to go undisturbed for weeks at a time.
Reducing clutter in garages, attics, basements, and storage areas makes those spaces far less appealing. Move firewood, stacked boxes, and debris away from your home’s foundation, since spiders congregate around building exteriors and migrate inside through gaps. Trim shrubs, vines, and tree branches that touch the house, as these create direct bridges from outdoors to your walls and eaves.
Seal entry points with tight-fitting window screens and door sweeps. In Florida, where doors and windows are often opened frequently, these physical barriers matter more than in cooler climates. Switching outdoor lights near entrances to yellow or sodium vapor bulbs also helps. These attract fewer night-flying insects, which in turn means fewer spiders gathering near your doors to feed on them.
For persistent problems, a perimeter insecticide spray around door thresholds, garage entrances, foundation vents, and the bottom edge of siding can reduce spider entry from outside. In Florida’s warm climate, these treatments may need reapplication monthly or every other month during the most active seasons.