Spider Eggs: All You Need to Know in a Jiffy

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Spiders are fascinating creatures, and their reproduction process is no exception. One area of interest is their eggs, which are laid in silk sacs and contain spiderlings waiting to hatch. To better understand these arachnids, let’s dive into the details of spider eggs.

As you encounter spider eggs, it’s important to know that they can come in different sizes and colors, depending on the species. For instance, some may be small and white, while others could be larger and brown. They are typically found in hidden corners, nooks, or even on plants outside your home.

Keep in mind that spiders play a vital role in maintaining a healthy ecosystem, as they control insect populations. As we explore this topic, you’ll learn everything you need to know about spider eggs and their importance in the world of spiders.

Understanding Spiders

Spiders are fascinating creatures with over 48,000 different spider species around the world. You might encounter some common species such as the wolf spider, black widow spider, brown recluse spiders, brown widow spider, or even tarantulas.

Each spider is unique in its own way, but they all share certain common characteristics that make them stand out in the world of arachnids. Some examples of shared characteristics include the ability to produce silk and having eight legs.

Here’s a comparison table highlighting the key features of some common spider species:

Spider Species Size Color Habitat Diet
Wolf Spider 0.4 – 1.38 inches (1 – 35 mm) Brown Grasslands, forests, suburbs Insects
Black Widow Spider 0.13 – 1.57 inches (3.5 – 40 mm) Black with red mark Warm regions, under rocks, in firewood Insects
Brown Recluse Spider 0.24 – 0.79 inches (6 – 20 mm) Light brown Dry, dark, undisturbed areas like woodpiles, basements, and closets Insects
Brown Widow Spider 0.39 – 1.57 inches (10 – 40 mm) Dark brown to black Tropical and subtropical regions, under eaves, in potted plants, garages, and fences Insects
Tarantulas Up to 5 inches (12 centimeters) Varies Various regions, burrows or tree holes Insects, small mammals

When you encounter spiders, it’s essential to know some of their key features to understand how they function. Some spider species are venomous, such as the black widow and brown recluse spiders, and their bites can pose a threat to humans. On the other hand, most spiders, like the wolf spider and tarantulas, are harmless and help control insect populations.

It’s also important to note that not all spiders spin webs to catch prey. Many spiders, like the wolf spider, are hunters and do not rely on webs. However, they still use silk for other purposes, like protecting their eggs.

Understanding spiders can help you appreciate their significant role in ecosystems, and knowing how to identify them can keep you safe during your outdoor adventures.

Spider Anatomy

As you learn about spider eggs, it’s essential to understand some basics about spider anatomy. Adult female spiders play a vital role in the reproduction process as they lay eggs and protect them.

Spiders go through a process called molting as they grow and develop. Molting is when a spider sheds its exoskeleton or outer skin to make room for growth. This process occurs multiple times before they reach sexual maturity.

  • Sexual maturity varies among spider species.
  • Lifespan also differs depending on species.

For example, some spiders may reach sexual maturity within a few months, while others may take years. It’s essential to know that the female spider’s primary objective is protecting their eggs once they have been laid. These are some basic behaviors and characteristics that help in this process:

  • Adult female spiders often guard their eggs.
  • Spiders use different strategies to keep predators away from their eggs.
  • Egg sacs may be hidden or camouflaged in the web or their habitat.

As you discover more about spider eggs, remembering these fundamental aspects of spider anatomy and behavior will enhance your understanding of the reproduction process. The importance of adult female spiders, along with their molting, sexual maturity, and lifespan, play a crucial role in the existence of these fascinating creatures.

All About Spider Eggs

Color, Size and Shape

Spider egg sacs come in various colors, sizes, and shapes. They can be:

  • White
  • Cream
  • Dark brown
  • Cream-white

The shape of the egg sac may be round or more irregular depending on the species. The size of the sac can vary as well, with some being as small as a few millimeters and others growing larger.

Where Spiders Lay Their Eggs

Spiders lay their eggs in various locations, such as:

  • Leaves
  • Attics
  • Basements
  • Woodpiles
  • Nest areas
  • Rocks

They typically choose locations that provide protection and safety for their spiderlings.

Lifecycle of Spider Eggs

The lifecycle of spider eggs follows a simple process:

  1. The female spider lays eggs and wraps them in a silk sac.
  2. The eggs hatch within the sac, producing spiderlings.
  3. Spiderlings grow, molt, and develop until they’re ready to leave the nest area and disperse.

Identifying spider eggs and their egg sacs can be essential for controlling and managing spider populations.

Common Species and Their Egg Characteristics

Here’s a comparison table of common species and their egg characteristics:

Species Egg Sac Color Shape Size Location
Black widow spider Cream-white Round, teardrop 1.5 cm Hidden in dark areas (woodpiles, rocks)
Yellow garden spider White Tear drop 2.5-4 cm Suspended within the spider’s web
Common house spider Beige Square, round 2-4 mm High corners of rooms, window frames
Cellar spiders White Disc-shaped Approximately 3 mm In dark corners of a cellar or attic

Knowing the characteristics of the egg sacs will make it easier for you to identify the spider species and deal with them accordingly.

Remember to always be cautious when handling spider eggs and spiderlings and to consult a professional if you’re unsure about the species or how to remove them safely.

Preventing Infestation

Indoor Prevention

To tackle a spider infestation indoors, start by vacuuming regularly. Your vacuum cleaner can help you get rid of spider eggs hidden in corners, on ceilings, and under furniture. For hard-to-reach places, use a broom to sweep away webs and egg sacs.

To deter spiders from moving in, reduce clutter around your home. Spiders love dark and secluded spaces, so keeping your living areas neat and tidy is essential. Another helpful method is using essential oils, such as:

  • Peppermint oil
  • Lemon oil
  • Tea tree oil
  • Cedar oil
    These oils can repel spiders and help in maintaining a spider-free environment.

Outdoor Prevention

For outdoor prevention, focus on removing ideal habitats for spiders. You should:

  • Remove woodpiles and rocks near your home, as they attract spiders.
  • Regularly trim bushes and shrubs to prevent spiders from nesting.
  • Seal any gaps and cracks that spiders may use to enter your home.

By taking these precautions, you can effectively reduce the chances of a spider infestation in and around your home. Remember, prevention is the key to maintaining a pest-free living space.

Dealing with an Infestation

When you find yourself dealing with a spider infestation in your home, there are different options to tackle the problem. In this section, we will discuss both home remedies and professional pest control methods.

Home Remedies

There are a few home remedies you can try to help control and dispose of spider infestations:

  • Bleach solution: Mix one part bleach to three parts water in a spray bottle, and spray it directly onto the spiders and their webs. This may help kill them and clear the affected area.
  • Fly swatter: Use a fly swatter to manually kill spiders when you see them. While this may not be a long-term solution, it can provide temporary relief.
  • Natural repellents: Some essential oils, like peppermint and eucalyptus, can act as natural spider repellents. Spray the oils around the infested area and entry points to help deter spiders.

Pros of Home Remedies:

  • Inexpensive and readily available
  • You can start immediately

Cons of Home Remedies:

  • May not be effective for severe infestations
  • Requires consistent effort

Professional Pest Control

When home remedies aren’t enough to handle a spider infestation, consider hiring a professional pest control service. These experts have the tools and knowledge needed to effectively treat and dispose of spider infestations in your home.

Pros of Professional Pest Control:

  • Highly effective and tailored specifically to your home and infestation
  • Can provide long-lasting solutions and prevention strategies

Cons of Professional Pest Control:

  • Can be more expensive than home remedies
  • May require ongoing maintenance appointments

In summary, dealing with a spider infestation can be challenging, but there are both home remedies and professional services available to help you regain control of your living space. Choose the option that best suits your needs, and remember that maintaining a clean home can help prevent future infestations.

Ecological Significance of Spiders and Their Eggs

Spiders are amazing creatures that play a crucial role in our ecosystem. They help control the population of mosquitoes, flies, and other pests by preying on them. Because of this, they act as natural predators and contribute to maintaining the balance in nature.

Insects like mosquitoes can become a nuisance and even transmit diseases, so it’s beneficial to have spiders around. For instance, the notorious black widow spider feeds on mosquitoes and other insects. However, be cautious because this species is venomous.

When it comes to reproduction, spiders lay their eggs in clusters, sometimes covering them with a sheet of silk for protection. Having a safe place for their eggs is essential, as humidity and temperature can affect their development.

Some spiders, such as the brown recluse, lay their eggs in secluded places like garages or basements. This is important for their survival, as it helps shield them from predators and environmental factors.

While spiders can be a little creepy, they play a vital role in maintaining ecological balance. It’s essential to understand their significance and learn to appreciate these amazing creatures for the help they provide in controlling unwanted pests. So next time you spot a spider or its eggs, remember the benefits they bring to your environment!

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Black and Yellow Orb Weaver with Eggsack


Please help!
I have a big female spider living outside my house. It has attached itself to the back of the house. She has three sacs now. This morning I found her and the third baby sac on the back screen door. I don’t want to harm the spider but rather relocate it, BUT I really want to know what kind of spider it is. Please find the attached pic. I hope that you can help. Thank you.
Suffolk, VA

Hi Charlotte,
Your letter doesn’t really indicate why you feel it is necessary to relocate this magnificent Argiope aurantia who found an ideal location for her nursery. Argiope aurantia has numerous common names, that are sometimes confusing, like Garden Spider, Black and Yellow Orbweaver, and Golden Orbweaver. She can and will bite if provoked, but she is not a threat to you or your family.

Letter 2 – Spider Egg Sac from Australia


Subject: Spider Egg Sac
Location: Adelaide, Australia
February 4, 2016 8:45 pm
Dear Bugman,
We found a spider’s egg sac hanging on our painting easel. It was round and white and grey, and it was hanging on a thread. We looked it up and decided it looked like the egg sac of a two-tailed spider, but we aren’t sure if these spiders live where we are.
Yesterday we noticed it had started to open. We looked inside with our microscope and saw baby spiders! Do you know what type they are? What sort of home or food do they need?
We really like spiders, especially peacock spiders!
Signature: From the Kangaroo’s Room (3 to 6 year olds)

Spider Egg Sac
Spider Egg Sac

Dear Kangaroo’ Room kids,
We will attempt to identify your Spider Egg Sac, but our gut feeling is that this is an Orbweaver Egg Sac.  What we find most surprising is the few individual spiderlings inside.  They also seem quite large to be hatchlings.  Normally we expect to see hundreds of spiderlings emerge from an Egg Sac.  Perhaps a survival strategy for this species is to have the hatchlings cannibalize one another while still in the egg sac, ensuring that the strongest survive, and freeing them from having to hunt for food while very young.  Spiders are predators.  Try feeding them small insects like Aphids.

Spider Egg Sac
Spider Egg Sac
Spiderlings in Egg Sac
Spiderlings in Egg Sac

Letter 3 – Bolas Spider Eggs


Subject: Bolsa spidea eggs?
Location: Anaheim, CA
January 1, 2015 4:36 pm
Howdy, these were found in a heap between avocado leaves. Can you ID? They’re about 1cm diameter, about 10 of them, tangled in sticky web, hard shell.
Signature: Becky G

Bolas Spider Egg Sacs
Bolas Spider Egg Sacs

Happy New Year Becky G,
We agree with you that these are Bolas Spider Egg Sacs, not those of a Bolsa Spidea.  Bolas Spiders are very well camouflaged and are difficult to find.  The egg sacs we reported on in November appear to have been parasitized, but we have hopes that a few individuals will hatch to perpetuate the species in our garden.

Letter 4 – Bolas Spider with Egg Sac


Subject: What is this?
Location: Northern Ohio
September 21, 2015 4:35 am
We found this next to our raised garden. I’ve never seen anything like it. Is it a spider or what? The “vase looking” nest is interesting, too.
Signature: Ohio

Bolas Spider with Egg Sac
Bolas Spider with Egg Sac

Dear Ohio,
You are correct that this Egg Sac was made by a spider, and if you look closely at the roundish white and brown object at the bottom of the Egg Sac, you can make out the body of the female Bolas Spider in the genus
Mastophora that is guarding the Egg Sac.  The female Bolas Spider is an excellent bird dropping mimic, and she can be expected to lay several more Egg Sacs before dying at the onset of cold weather.  Bolas Spiders like other Orbweavers are considered harmless, yet beneficial creatures in the garden.

Bolas Spider with Egg Sac
Bolas Spider with Egg Sac

Letter 5 – Basilica Orbweaver, not Cyclosa bifurca


Hi Spiderman!
Ok..Im stumped. Never seen anything like this. I live in Milton, Delaware…….there seems to be 5 round eggcases within the cocoon. Any idea what they might be? I always heard colored spiders were poisionous. Is this the case? Thanks!!

Wow Connie,
Nice photo of Cyclosa bifurca. Here is what Comstock has to say: “The strange form of the abdomen sharply distinguishes this species from the othe species of Cyclosa in our fauna. The abdomen is long; the basal half bears two pairs of humps; the caudal half is more slender and is bifurcate at the tip. The body is green mottled with white; there is a light wavy band on the side of the abdomen; and the abdomen is bordered with a black line above, back of the humps. On the ventral side of the abdomen, there is a bright red spot between the epigastric furrow and the spinnerets. The legs are banded with reddish brown. I found this to be a common species near Miami, Fla. I first found it in the jungle near the shore of the bay, where it made an orb-web with a string of eggsacs across it like a stabilimentum.” Thank you for your wonderful addition to our site, especially since I could not find any photos online.

November 28, 2010
Today we received a new identification request which led us on an identification search on BugGuide that ended with a new identification for this egg sac configuration:  the Basilica Spider,
Mecynogea lemniscata.


  • Bugman

    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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