Daddy Long Legs: Spider, Insect, or Something Else

The name “daddy long legs” causes confusion because it refers to three completely different animals. While some are harmless insects, others are arachnids with a surprising myth about their venom.

Number of distinct animals called daddy long legs: 3 | Cellar spider species worldwide: Over 2,000 | Crane fly species in the UK: 94 | Harvestmen species worldwide: Over 6,500

The table below summarizes the key differences among the three animals commonly called daddy long legs.

The implication: the three creatures share a name but little else, and their biology determines how they interact with humans.

Is a daddy long legs a spider or an insect?

The three animals called daddy long legs

The common name “daddy long legs” applies to at least three distinct arthropods: cellar spiders (Pholcidae), harvestmen (Opiliones), and crane flies (Tipulidae). Each belongs to a different taxonomic group. The Burke Museum explains that people encounter different creatures in different settings, leading to the shared name.

Cellar spiders (Pholcidae)

Cellar spiders are true spiders. They have eight legs and two body segments. The Wildlife Trusts notes they are almost always found indoors, in warm, stable environments like houses and cellars. The cosmopolitan species Pholcus phalangioides is commonly called the daddy long-legs spider – Wikipedia.

Harvestmen (Opiliones)

Harvestmen are arachnids but not spiders. They have a single oval body, unlike spiders with a separated body plan – JG Pest Control. The Burke Museum confirms that many Americans use “daddy longlegs” for harvestmen.

Crane flies (Tipulidae)

Crane flies are insects, not spiders. They have six legs and one pair of wings, and are often described as fluttery and slow – JG Pest Control. In the UK, “daddy long legs” almost always refers to crane flies – JG Pest Control.

The pattern: the name is a catch-all for long-legged arthropods, but the actual classification makes a huge difference in behavior and risk.

Why is it called daddy long legs?

Origin of the name

The name likely refers to the long, thin legs that all three animals share. The exact origin is unclear, but it has been used for centuries. Just as the name Tyrannosaurus Rex: Facts, Extinction, and Meaning is often misunderstood, the term “daddy long legs” creates confusion because it is applied to multiple creatures.

Regional variations

The Burke Museum notes that British people, some Canadians, and some southeastern Americans use “daddy” terms for crane flies. In contrast, many Americans use “daddy longlegs” for harvestmen. The Wikipedia entry on Pholcidae states that the term is used for several arthropod groups, not just one species.

The catch: regional differences mean that the same word can describe a flying insect in one country and a spider in another.

Are daddy long legs harmless?

Can daddy long legs bite?

Cellar spiders can bite, but bites are rare and trivial – JG Pest Control. Harvestmen cannot bite because they have no venom glands – Terminix. Crane flies do not bite at all – JG Pest Control.

Are they venomous?

Cellar spiders produce venom, but it is harmless to humans – Terminix. Harvestmen have no venom glands. Crane flies have no venom. The famous claim that cellar spiders are the most venomous spiders but cannot bite humans is a myth – JG Pest Control.

Is it safe to have them indoors?

Yes. All three are harmless to humans. UF/IFAS Blogs debunks the myth that daddy long legs are dangerous. They are beneficial in controlling pests (cellar spiders eat other insects, crane fly larvae aerate soil).

“The myth that daddy long legs are the most venomous spiders is completely false.” – UF/IFAS Blog

“Much of the confusion stems from the common name being applied to different creatures.” – Burke Museum

The implication: none of the animals pose any threat, and the urban legend is entirely unsupported.

What are the biggest spiders in Ireland?

Common large spiders in Ireland

In Ireland, the largest spiders include house spiders (Tegenaria) and orb-weavers (Araneus). The Wildlife Trusts notes that cellar spiders are also common indoors but are not particularly large.

Are daddy long legs among them?

In Ireland, “daddy long legs” usually refers to the crane fly, not a spider – JG Pest Control. So the largest spiders in Ireland are not daddy long legs. The crane fly has a long body and legs but is an insect, not a spider.

What this means: the question itself is based on a regional naming quirk.

Why don’t you see daddy long legs anymore?

Factors affecting crane fly populations

Crane flies are seasonal; adults emerge in late summer and autumn, often attracted to lights – JG Pest Control. Their presence varies yearly with weather and habitat conditions.

Seasonal variation

People may notice fewer crane flies in certain years due to dry springs or changes in soil moisture. The UK has 94 crane fly species – JG Pest Control – so their abundance fluctuates.

Urbanization and climate

There is no evidence of a widespread decline. Harvestmen and cellar spiders remain common – Burke Museum. The perception of “disappearing” may be due to shorter attention spans or changes in lighting.

The pattern: seasonal and environmental factors influence visibility, but the creatures are still present.

Like the myths surrounding William Wallace, the myths about daddy long legs are widespread. Read more about William Wallace: The Real Story vs. Braveheart Myths & Facts.