Cellar Spider Facts: Essential Information for Quick Understanding

Cellar spiders are a fascinating species commonly found in dark, secluded areas of homes and buildings. Although they may look intimidating due to their long legs and distinctive appearance, these spiders are actually quite harmless. In this article, we’ll explore everything you need to know about cellar spiders, from their habits to their benefits.

There are two main types of cellar spiders: long-bodied and short-bodied. The female long-bodied cellar spider measures approximately 1/4-5/16 inch long with legs extending another 2 inches, while the female short-bodied cellar spider has a 1/16 inch long body with legs extending about 5/16 inch source. Both types of cellar spiders prefer dark and moist environments, making them common inhabitants of basements, crawlspaces, and cellars.

Some interesting characteristics of cellar spiders include:

  • Long, delicate legs
  • Gray, tan, or whitish color
  • Small body size
  • Remarkable habit of “vibrating” or bouncing in their webs when alarmed source.

In the next sections, we will dive deeper into the world of cellar spiders, exploring their behaviors, life cycle, and the potential benefits they bring to our homes.

What Is a Cellar Spider?

Species and Classification

Cellar spiders belong to the family Pholcidae and are often referred to as “daddy longlegs.” However, it is important to note that there are two other unrelated arachnids commonly called daddy longlegs: harvestmen and craneflies.

There are two main types of cellar spiders:

  • Long-bodied cellar spiders
  • Short-bodied cellar spiders


Cellar spiders have a distinct appearance, with their most noticeable features being their long, slender legs. Here is a comparison of the two types of cellar spiders:

Feature Long-bodied Cellar Spider Short-bodied Cellar Spider
Body length 1/4-5/16 inch1 1/16 inch1
Leg length 2 inches1 5/16 inch1
Color Pale gray to light tan2 Similar to long-bodied spiders
Eyes 8 eyes, arranged in 2 rows1 Similar to long-bodied spiders

Cellar spiders build loose, irregular webs in corners near the ceiling or floor2. They are not known to be harmful and can help control other pests by feeding on insects in and around your home.

Anatomy of a Cellar Spider

Body and Legs

The body of a typical cellar spider is quite small, while the legs are extremely long and thin, giving them a wispy appearance. To provide more detail:

  • Female long-bodied cellar spiders: body is approximately 1/4-5/16 inch long, and legs extend another 2 inches.
  • Female short-bodied cellar spiders: body is around 1/16 inch long, and legs extend about 5/16 inch.

The tarsi, or “feet,” of cellar spiders are flexible, adding to the fragile impression they give.

Abdomen and Color

Cellar spiders have a tubular abdomen that is gray, tan, or whitish in color. Their small body size and neutral coloration help them to blend into their environment, making them inconspicuous.

Venom and Fangs

While cellar spiders are venomous, their venom is not considered harmful to humans. Their fangs are very small, and they typically use their long legs to cast silk onto their prey, immobilizing it from a safe distance.

To summarize:

  • Cellar spiders have a small body and long, thin legs.
  • Their tubular abdomen can be gray, tan, or whitish in color.
  • They are venomous but not harmful to humans.
Feature Cellar Spiders
Body size Small
Leg length Extremely long
Abdomen shape Tubular
Color Gray, tan, or whitish
Venom Present but not harmful to humans

Habitats and Distribution

Typical Areas

Cellar spiders are commonly found in:

  • Cellars: As their name suggests, these spiders are often spotted in cellars.
  • Basements: They prefer damp, dark environments like basements.
  • Crawl spaces: Crawl spaces and other undisturbed areas in the house are perfect habitats for these spiders.
  • Attics: Some species of cellar spiders may also be seen in attics or other moist areas of the house.
  • Garages: They can be found in garages, especially near crevices.
  • Warehouses: These spiders sometimes make their homes in warehouses.

They tend to build irregular webs to catch their prey.

Range and Distribution

Cellar spiders have a wide geographic distribution. They can be found in:

  • Buildings: They are commonly spotted in various types of buildings.
  • Caves: Some species may also thrive in caves and other damp areas.
  • Spider-infested areas: In areas where spider infestations are common, cellar spiders may coexist with other species like the black widow.
Area Presence of Cellar Spiders
Cellars Yes
Basements Yes
Crawl spaces Yes
Attics Yes
Garages Yes
Warehouses Yes
Caves Yes (some species)
Spider-infested areas Yes (sometimes)

Overall, cellar spiders are widespread and can be found in many different environments where moisture and undisturbed spaces are present.

Reproduction and Life Cycle

Mating Behavior

Cellar spiders exhibit unique mating rituals, where males often use their long legs to tap and vibrate the female’s web. This behavior is crucial in attracting the attention of the female cellar spider.

Egg Sacs

Female long-bodied cellar spiders can produce about three egg sacs over their lifetime 1, each containing 13-60 eggs. They hold the egg sacs using their jaws and legs, ensuring the safety and protection of their offspring.


Upon hatching:

  • Spiderlings are tiny versions of adult cellar spiders.
  • They go through several molts before reaching adulthood.

Diet and Hunting Techniques

Common Prey

Cellar spiders, being part of the Pholcidae family, mainly feed on insects and other arachnids. Some examples of their prey include:

  • Flies
  • Mosquitoes
  • Ants
  • Small moths

These spiders play a vital role in natural pest control, as they help reduce the population of common pests found in homes and gardens.

Cobwebs and Loose Webs

Cellar spiders create silk webs to catch their prey. Their webs, often found in cellars, corners, and dark spaces, have some unique features:

  • Irregular shape
  • Loose structure
  • Resembling cobwebs

When comparing cellar spiders to cobweb spiders, their webs have some differences:

Feature Cellar Spider Webs Cobweb Spider Webs
Shape Irregular Irregular
Structure Loose Dense
Placement Ceilings and corners Corners and edges

Once prey is caught in their web, cellar spiders use their long legs to quickly reach and immobilize their victims with venom. The spiders then consume their prey, keeping the environment cleaner and reducing the number of pest insects.

In conclusion, cellar spiders are effective hunters that utilize their webs and venom to capture a variety of insects, making them an excellent form of natural pest control. Their webs, though somewhat similar to cobwebs, have distinct differences in structure and placement.

Dealing with Cellar Spiders

Prevention Measures

To protect your home from cellar spiders, consider implementing the following preventive measures:

  • Regularly clean and vacuum your home, focusing on corners, crevices, and dark spaces where spiders like to hide.
  • Use a dehumidifier to reduce humidity levels in damp areas such as basements and crawlspaces.
  • Seal any cracks or gaps in your home’s exterior with weatherstripping and caulk to prevent spiders from entering.
  • Install door sweeps on exterior doors to keep spiders out.
  • Replace standard outdoor lights with yellow light bulbs, which attract fewer insects and subsequently fewer spiders looking for food.

How to Remove Cellar Spiders

If you already have cellar spiders in your home, here are some methods for removing them:

  • Use a vacuum cleaner with a hose attachment to remove spiders and their webs from corners and crevices.
  • Sweep up spiders and their webs using a long-handled broom, then dispose of them outside.
  • For more severe infestations, consider using an insecticide specifically labeled for spiders. Be sure to read and follow the product label instructions for safe and effective spider control.
Method Pros Cons
Vacuuming Quick and easy; no chemicals needed May not reach all spiders and webs
Broom Chemical-free; can reach high places May require more effort to remove all
Insecticide Effective for severe infestations Chemicals may pose risks if misused

Remember, cellar spiders are generally harmless and may even help control other insect populations in your home. However, if you prefer to keep them out or remove them from your living space, these prevention and removal tips can help.

Misconceptions and Myths

One common myth about cellar spiders is that they are dangerous or harmful creatures. In reality, these spiders are harmless and are not known to bite people. Their appearance might be unsettling to some, but there is no need to fear them.

It is also worth mentioning the misconception that cellar spiders are “daddy long legs” spiders. Although they have similar appearances, cellar spiders and daddy long legs are actually distinct species. Cellar spiders belong to the family Pholcidae, while daddy long legs belong to the family Pholcidae or the order Opiliones.

Here is a comparison table outlining their differences:

Feature Cellar Spiders Daddy Long Legs
Appearance Long, delicate legs Slightly shorter legs
Habitat Basements, cellars, dark corners Gardens, grasslands
Harm to Humans Harmless, not known to bite Also harmless

Another myth about cellar spiders is that their vibrating behavior is an aggressive act. In reality, this unique characteristic of vibrating spiders when disturbed is a defensive technique. It helps them avoid being detected by potential predators or threats, as the rapid movement creates a blurry visual effect.

Lastly, it’s essential to debunk the killer spider myth. Some rumours suggest that cellar spiders are deadly or can kill black widow spiders. In truth, cellar spiders are not killers and do not pose any serious threat to humans or other spiders. They may prey on other insects, but they are not venomous like black widow spiders.

To sum up, cellar spiders are:

  • Harmless and not known to bite
  • Often confused with daddy long legs
  • Vibrating spiders for defense, not aggression
  • Not killer spiders as myths suggest
  • Distinct from black widow spiders


  1. Clemson University – Cellar Spiders 2 3 4 5 6
  2. University of Minnesota Extension – Spiders 2


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    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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14 thoughts on “Cellar Spider Facts: Essential Information for Quick Understanding”

  1. I am currently living in Germany for the next year and I have been finding these spiders all over my house. They usually stay up near the ceiling or in corners of the room, but they sometimes will drop down from the ceiling on a strand of their silk. Due to the number of these spiders I’m finding in my home, I feel I have to ask if they are at all poisonous? Personally I’ve always been fascinated by spiders and it’s never bothered me before to have them around but due to the fact that i have small children in my home and these spiders being so numerous,I’m concerned about the possibility of one of them being bitten.

  2. While all spiders are venomous, not all venoms are harmful to us, and the cellar spider’s venom is one of them. The spiders also rarely bite and prefer to flee. Also, it’s a myth that these spiders have the deadliest venom in the world to humans but fangs are too small to pierce our skin. Their fangs can in fact pierce skin, but their venom isn’t dangerous to us and they rarely bite.

  3. I have cellar spiders too (although I’m an arachnaphobe, these spiders are so flimsy and harmless I’m not too fearful of them) and have seen a great many over the last 15 years, but I have never seen a green one. “Mine” are always beige/grey. Amazing.

  4. I would say it’ s from their last food – the Pholcus I am keeping for certain ID was yellow at first but after a fly’ s eyes it turned reddish and after more meals – brownish, – as their bodies are semitransparent. This one might have had eaten a lacewing or a green bug for example.

  5. I came across this page trying to find more about a green spider I just saw. She was very similar to the one in the above photograph. I wondered as well re the type I encountered possibly being color-adaptive, as she was found among several green plant flakes; I saw the spider briefly as she ran due to my accidentally disturbing her for not seeing her resting or lurking among the flakes.

  6. Sorry – PS – some difference to the photo, though: she had a very small body and very long legs. I thought she might be a (proper) daddy long legs, but she only had one segment that I could see of her tiny body so presumably she’s a type of cellar spider


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