I have always been fascinated by the different kinds of spiders in my garden, and among them, the cellar spider is one of the most intriguing. These spiders, belonging to the family Pholcidae, are commonly found in dark and damp places, including my basement and garden shed. With their long, delicate legs and small bodies, they are sometimes mistaken for daddy long legs, but they are quite different.
What is a Cellar Spider?
Appearance and Size
Cellar spiders are small-bodied but have long, thin legs, which make them look much larger. Their body length ranges from 2 to 10 mm, but their legs can extend up to 50 mm. The long-bodied cellar spider (Pholcus phalangioides) is the most common species I encounter in my garden shed.
Behavior
One of the most fascinating things I’ve noticed about cellar spiders is their vibrating defense mechanism. If I disturb their web, they start shaking rapidly, which makes them harder for predators to catch. They are also excellent hunters, preying on various insects and even other spiders in my garden.
Where Do Cellar Spiders Live?
Habitat
I often find these spiders in dark, humid environments, such as the corners of my basement, under wooden logs in my garden, and inside my old gardening shed. They prefer places where they can build their delicate, messy-looking webs without much disturbance.
Can Cellar Spiders Live Outside?
Yes! While they are commonly found indoors, I have also seen them living under rocks, in tree bark, and even in my greenhouse. They prefer shaded areas where they can catch insects without much effort.
What Do Cellar Spiders Eat?
Diet and Hunting Habits
Cellar spiders are natural pest controllers in my home and garden. They feed on:
- Flies and mosquitoes (which is a big help!)
- Ants and other small insects
- Other spiders, including house spiders and dangerous species like black widows and brown recluses
I once observed a cellar spider capturing a much larger spider in its web. It was fascinating to see how these seemingly fragile creatures could be such effective hunters.
How Long Do Cellar Spiders Live?
Lifespan
From my observations and research, cellar spiders live for about 1 to 3 years. Some have survived even longer in the right conditions. They can also go without food for weeks by slowing down their metabolism.
Cellar Spider Eggs and Reproduction
During the warmer months, I often find cellar spider egg sacs attached to their webs. The females carry their egg sacs in their fangs, protecting them until they hatch. The tiny baby spiders emerge and quickly start building their own webs.
Are Cellar Spiders Dangerous?
Venom and Bites
A common myth is that cellar spiders have the most potent venom but cannot bite humans—this is not true. While they do have venom, it is harmless to humans. Their fangs are too small and weak to penetrate human skin. I have handled cellar spiders many times, and they have never shown any aggression.
Do Cellar Spiders Bite?
I get this question a lot. From my experience, cellar spiders do not bite humans. Even if they could, their venom is only effective on small insects. They are completely harmless and even beneficial in reducing other pest populations.
Evolution and Adaptation
How Have Cellar Spiders Evolved?
Cellar spiders belong to the Pholcidae family and have evolved over millions of years to thrive in dark, damp environments. Their thin, long legs and web-building strategies give them an advantage when it comes to catching prey and avoiding predators.
How to Get Rid of Cellar Spiders (If Necessary)
Even though I appreciate having them in my garden, I understand that some people prefer to remove them from their homes. If you want to get rid of cellar spiders, try these methods:
- Keep areas clean and dust-free – They love undisturbed spaces.
- Seal cracks and gaps – Prevent them from entering your home.
- Use natural repellents – Essential oils like peppermint can deter them.
Cellar Spider vs. Daddy Long Legs
Many people confuse cellar spiders with daddy long legs, but they are actually different creatures. Daddy long legs, also called harvestmen, belong to the Opiliones order, while cellar spiders are true spiders from the Pholcidae family.
Physical Differences
- Cellar spiders have long, thin legs but also possess two body segments like other spiders.
- Daddy long legs have a single, fused body segment with no separation.
Web-Building Habits
- Cellar spiders spin messy, irregular webs where they catch prey.
- Daddy long legs do not make webs; they actively hunt for food.
Diet
- Cellar spiders eat insects, including other spiders.
- Daddy long legs consume decaying plant matter and small insects.
Venom
- Cellar spiders have venom but are harmless to humans.
- Daddy long legs do not have venom and cannot bite humans.
Cellar Spider vs. Brown Recluse
Cellar spiders are often mistaken for brown recluse spiders, which are more dangerous. Here’s how to tell them apart.
Size and Color
- Cellar spiders are thin and light-colored with long legs.
- Brown recluses have a more compact body, with a violin-shaped marking on their back.
Webbing and Habitat
- Cellar spiders make loose, messy webs in corners.
- Brown recluses create irregular silk retreats in dark places.
Behavior
- Cellar spiders shake their webs when disturbed.
- Brown recluses are solitary hunters and avoid confrontation.
Venom Danger
- Cellar spider venom is harmless to humans.
- Brown recluse venom can cause necrotic skin damage and requires medical attention.
Do Cellar Spiders Eat Other Spiders?
Yes, cellar spiders are skilled spider hunters and often eat other spider species.
What Spiders Do They Eat?
- House spiders that get caught in their web.
- Black widows, making them beneficial in homes.
- Brown recluses, helping control their population.
How Do They Capture Prey?
- They entangle prey in their web and wrap them in silk.
- They use venom to immobilize their target before consuming it.
Hunting Style
- Passive hunting – waiting for prey in their web.
- Active hunting – attacking trapped prey aggressively.
Why Is This Beneficial?
- Helps control dangerous spider populations.
- Reduces household pests naturally.
Are Cellar Spiders Poisonous?
Many people wonder if cellar spiders are poisonous, but the truth is, they are harmless to humans.
Do They Have Venom?
- Yes, but it is mild and only effective against small insects.
- Their fangs are too small to penetrate human skin.
Can They Bite Humans?
- Bites are extremely rare and usually go unnoticed.
- No reported harmful reactions from their bite.
Myth: The Most Venomous Spider
- A common myth claims cellar spiders have the strongest venom but cannot bite humans.
- This is false – their venom is weak and non-toxic to people.
Should You Worry About Cellar Spiders?
- No, they are completely harmless.
- They help control other pests in homes and gardens.
