Looking around your home, you’ve surely seen a spiderweb or two in places like the ceiling, the attic, or in the basement. Many different kinds of spiders live in homes and buildings, the majority of which pose no threat to humans. Here’s what you need to know about cellar spiders, a very common spider that isn’t unusual to spot in your house.
What Are Cellar Spiders?
Cellar spiders belong to the scientific group Pholcidae. Like all other kinds of spiders, their bodies have two segments: the cephalothorax in the front and the abdomen in the back. What makes this spider different from other types is that it has very long, thin legs. Because of this, you might know cellar spiders by the nickname “daddy longlegs.” However, this name can also refer to an insect called the harvestman, which looks like a spider but is not one.
Cellar spider size. About 20 different kinds of cellar spiders live throughout the US and Canada, so their size may vary depending on the type. Long-bodied cellar spiders have bodies that are 7 to 8 millimeters long and front legs can be between 45 to 50 millimeters long. Short-bodied cellar spiders are smaller, with a body that’s only millimeters long and front legs that typically reach 9.5 millimeters.
Cellar spider identification. Cellar spiders look fragile and wispy due to their very thin legs. They can be several different colors, including gray, tan, or yellowish. Some varieties of cellar spiders have dark coloring on their knees. Like other arachnids, they have eight eyes: two in the middle of their face and three that cluster around each of them. They also have eight legs.
The Cellar Spider Lifespan
Cellar spiders can live for two or more years past maturation. The female long-bodied cellar spider typically produces three egg sacs during her lifetime, each one holding between 13 and 60 eggs. Short-bodied cellar spiders may carry a little less. While most other species of spiders attach their egg sacs to their web, cellar spiders carry them in their mouthparts. When the spider eggs hatch, the spiderlings crawl out of their mother’s body. It takes about one year for a spiderling to develop into an adult cellar spider.
As the spiderlings grow, they shed their exoskeleton. This happens many times throughout their lives. Even though cellar spiders have a lifespan of a few years, many won’t live this long. They are prey for other insects and spiders, as well as small reptiles and mammals. Many people also remove them from their homes when they spot them.
Where Do Cellar Spiders Live?
Cellar spiders live all over the world. They live almost exclusively indoors, where they can take advantage of a stable temperature and not have to worry about the weather. In homes and buildings, cellar spiders create loose, messy webs in the corners of rooms near the ceiling, over windows, or over pipes. As the name suggests, cellar spiders like to hang out in places like basements, crawl spaces, or behind HVAC units.
Cellar spiders normally hang upside down from their webs. Some bounce quickly in their web to make it vibrate when they sense danger or a threat. Other cellar spiders will curl up to try and not be noticed.
What do cellar spiders eat? Cellar spiders use their webs to trap insects and feed on them. They’ll eat pretty much anything that gets stuck in their web, but the cellar spider diet typically includes:
- Mosquitoes
- Gnats
- Moths
- Flies
- Other spiders
Even though the cellar spider looks very fragile, it’s not afraid to prey on insects and spiders that are much larger than it is. Once it snags a meal in its web, the cellar spider will shake its web to ensure that the insect becomes as entangled as possible so that it can’t escape.
Do Cellar Spiders Bite?
Almost all spiders that are native to North America are venomous. That doesn’t necessarily make them dangerous, though. While many spiders bite their prey to inject it with venom, the cellar spider doesn’t. Even though it has fangs and venom glands, its fangs are quite short. Its venom is also weak, so the cellar spider has to depend on its silk web to immobilize any prey that comes near its web.
There’s a myth floating around out there that cellar spiders have the most poisonous venom out of all spiders and that only their short fangs keep them from being a threat to humans. However, there’s no research out there to prove this to be true. In reality, most spiders don’t bite humans unless they feel threatened to do so. 98% of spiders are harmless and don’t pose any threat to people. Even though a spider bite can be painful or uncomfortable, the venom is the dangerous part, not the bite itself.
How to Get Rid of Cellar Spiders
Cellar spiders are harmless and can be helpful in your home since they prey on annoying insects like mosquitoes and flies. However, not everyone wants to have their messy-looking webs hanging around when guests come over.
Prevention. Fortunately, there are several things that you can do to reduce the number of cellar spiders creeping around your home. The first step is to prevent them from entering in the first place. Start by sealing off any cracks around your home with a silicone-based caulk. You can install weatherstripping and doors that have a door sweep to stop insects from getting in.
The best way to eliminate spiders from your home is to cut off their food source as much as possible. Consider switching to yellow lightbulbs for your exterior lighting fixtures. This can reduce the number of flying insects that are typically attracted to bright lights. Using a dehumidifier in certain parts of your home to keep damp places dry should also reduce the number of insects and spiders.
Removing webs and spiders. You typically don’t need any chemicals to remove spiders from your home like you would need for other pests. Spiders, their webs, and their egg sacs can all be swept away with a broom or a vacuum. This is the fastest and most effective way to get rid of spiders in your home.