How Many Legs Does a Daddy Long Legs Have?
“Daddy long legs” is the rare common name that points at three unrelated creatures: an arachnid that isn’t a spider, an actual spider, and an insect. Two of them have eight legs; one has six. And the line everyone repeats — that they’re the most venomous spider alive but can’t bite you — is simply wrong.
Which daddy long legs do you mean?
One nickname, three unrelated animals. Tap each to see the leg count and whether it is even a spider.
The creature most correctly called a daddy long legs. One fused, oval body with no waist, no silk and no venom glands. It is found on every continent except Antarctica, and the lineage shows up in fossils over 400 million years old.
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Three animals, one nickname
The creature most correctly called a daddy long legs is the harvestman — order Opiliones, an arachnid but not a spider. The University of Washington’s Burke Museum, whose arachnologist Rod Crawford runs a long-running spider-myths page, is blunt about it: harvestmen have a single fused body with no waist, no silk and no venom glands at all.
The second animal is the cellar spider (family Pholcidae) — a real spider with two body segments and eight eyes, the one dangling in a messy web in your ceiling corner. The third, mostly in Britain, is the crane fly: an insect with six legs and wings that looks like a giant mosquito but cannot bite, because the adult barely has working mouthparts and lives only a few days.
The venom myth, finally settled
The claim is specific: the most venomous spider on Earth, saved from being deadly only by fangs too short to pierce skin. It collapses immediately. Harvestmen and crane flies have no venom whatsoever, so two of the three candidates are disqualified before you start.
That leaves the cellar spider, which does have venom — weak venom, studied and found unremarkable. MythBusters tackled it head-on in a 2004 episode: a cellar spider was induced to bite a host, and the result was a faint, harmless sting. A 2019 scientific paper revisited the question, confirmed the venom is no threat to humans, and explicitly tipped its hat to the show. The fangs-too-small story isn’t a near-miss with the truth; it never had a basis.
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The fast field test
You can settle it in two seconds. Count the legs first: six plus wings means crane fly, and you’re done. If it has eight, look at the body. One smooth oval with no obvious waist is a harvestman; a clear two-part body — a small head section and a separate abdomen — with a web nearby is a cellar spider.
One more oddity worth knowing: harvestmen can shed a leg to escape a predator, and the detached limb keeps twitching to distract it. They never grow it back, which is why you often see a harvestman walking on seven.
Sources
- Burke Museum (University of Washington), Spider Myths — Rod Crawford and Rick Vetter on the harvestman/cellar-spider/crane-fly confusion and the venom myth.
- MythBusters, Season 2 (2004) — on-camera test of the cellar-spider bite; a 2019 study confirming the venom is harmless and citing the episode.
- University of California (UC ANR) Bohart Museum — only Pholcid cellar spiders in the group have venom, too weak to affect humans.
- WebMD & Montana PBS “A Wilder View” — harvestmen (Opiliones) have one body segment, two eyes, no silk and no venom.
Frequently asked questions
Related
Eight legs, six legs, no venom, no spider — the only thing all three daddy long legs share is a name nobody can pin to one animal.