The terms "cellar spider" and "daddy long legs" are often used interchangeably, leading to significant confusion. However, these names actually refer to two distinct arachnid groups with key differences in their appearance, behavior, and even classification. This article will clarify the distinctions between these often-misunderstood creatures.
What is a Cellar Spider?
Cellar spiders, scientifically known as Pholcidae, are a family of small, delicate spiders commonly found in dark, damp places like cellars, basements, and sheds – hence their name. They're characterized by their long, thin legs, which are significantly longer than their body, and their generally pale, light brown or grayish coloration. They often build messy, irregular webs in corners and crevices. While their appearance might seem somewhat frightening to some, cellar spiders are generally harmless to humans. Their venom, while present, is considered too weak to affect humans.
How to Identify a Cellar Spider:
- Long, thin legs: These are disproportionately long compared to their body size.
- Small body: They have a relatively small body compared to their leg span.
- Irregular web: Their webs are often tangled and messy, unlike the neatly structured webs of many other spiders.
- Pale coloration: They are typically light brown, gray, or whitish in color.
- Segmented abdomen: Their abdomen is clearly divided into segments.
What are Daddy Long Legs?
The term "daddy long legs" is ambiguous and can refer to two entirely different creatures: harvestmen (order Opiliones) and cellar spiders (as discussed above). This ambiguity is the root of much of the confusion surrounding these arachnids.
Harvestmen (Opiliones): These are arachnids, but they are not spiders. They belong to a distinct order and lack several key spider characteristics. Harvestmen have a single body segment (unlike spiders, which have two), lack venom glands and spinnerets (silk-producing organs), and possess extremely long legs relative to their body size. They're often found outdoors in leaf litter, under rocks, and in similar habitats.
Key Differences Between Harvestmen and Spiders (including Cellar Spiders):
| Feature | Harvestmen (Daddy Long Legs) | Spiders (including Cellar Spiders) |
|---|---|---|
| Body Segments | One | Two (cephalothorax and abdomen) |
| Venom Glands | Absent | Present (though often weak in cellar spiders) |
| Spinnerets | Absent | Present |
| Pedipalps | Resemble legs | Often modified as pincers |
How to Identify a Harvestman (True Daddy Long Legs):
- Single body segment: Their body is a single, undivided unit.
- Extremely long legs: Their legs are exceptionally long in proportion to their body.
- No silk production: They don't spin webs.
- Usually found outdoors: While sometimes found near buildings, their primary habitat is outdoors.
- Lack of constriction between cephalothorax and abdomen: A key visual difference from spiders.
Are Daddy Long Legs Poisonous?
This is a frequently asked question, and the answer depends on which "daddy long legs" you're referring to.
Cellar Spiders: As mentioned, cellar spiders do have venom glands, but their venom is generally considered harmless to humans. There is no credible evidence supporting the widespread myth that their bite is deadly.
Harvestmen: Harvestmen lack venom glands entirely, rendering them completely harmless. They cannot bite in a way that would inject venom, even if they possessed it.
Are Cellar Spiders Dangerous?
No, cellar spiders are not dangerous to humans. Their bites are virtually undetectable, and their venom poses no significant threat. While they might be unsettling to some due to their appearance and the sheer number that can sometimes be found in one location, they are beneficial predators, helping to control populations of other insects.
Do Cellar Spiders Bite?
While cellar spiders possess venom glands, they rarely, if ever, bite humans. Their fangs are too small and weak to penetrate human skin effectively, and they generally prefer to avoid confrontation. Even if they did manage to bite, the venom is far too weak to cause any noticeable effects.
In Conclusion
The terms "cellar spider" and "daddy long legs" are not interchangeable. "Daddy long legs" is a misleading common name applied to both cellar spiders and harvestmen, which are distinct arachnids with significant biological differences. While both are generally harmless to humans, understanding their individual characteristics is crucial for accurate identification and dispelling common myths surrounding these fascinating creatures.
