Spider eggs in New Jersey: how to identify and remove them

Spider eggs can turn up in corners, basements, and window sills around your New Jersey home. This guide to spider eggs will help you find and eliminate these eggs before they hatch.

What do spider eggs look like?

Most spiders lay their eggs together in sacs rather than individually. These egg sacs are often white, cream, or yellowish, depending on the species. Some are yellowish-green or light brown. The sacs are usually orb-shaped, but some are conical, oblong, or lens-shaped. They also tend to have an irregular shape and texture as spiders wrap their eggs in silk to protect them.

As a general rule, egg sacs are roughly the same size as the spider that made them; usually no bigger than a quarter. Some spiders lay one egg sac while others lay several smaller ones. A single sac can contain anywhere from a handful of eggs to more than 2,000. Most contain around 100 to 200 eggs.

When and where do spiders lay eggs?

Most spiders will lay their eggs in the fall or spring. The average time for spider eggs to hatch is anywhere from 14 to 21 days, depending on the type of spider. This is why more spiders are often seen indoors in spring and fall, but overall, you may see more of them in summer and winter.

Year-round pest control (winter pest control included) is a great step toward keeping the spider population on your property under control.

Spiders get into our homes regardless of whether they carry their eggs with them or leave them in webs, burrows, or outside. By focusing on nesting areas and having strategies in place for winter, your home can be spider-free.

How to remove spider eggs

Always attempt to determine the species of spider before removing an egg sac. If it belongs to a dangerous species such as the black widow or brown recluse, the removal must be done by a professional.

Black widow egg sacs look whitish/grayish and often have a notch at the top. They usually contain 250 to 300 eggs. Brown recluse egg sacs are off-white or tan. They are flat on the bottom and rounded to cone-shaped on top. They also contain around 40 to 50 eggs. Both species prefer dark, sheltered, quiet corners.

Many DIY methods work for removing spider eggs, including vacuuming. Use a hose attachment to suck up the egg sac, then take the vacuum out immediately and dispose of the contents outside. Be careful— you don't want to prematurely rupture the egg sac because that will release hundreds of baby spiders.

Spraying will also work, so long as you use the right chemicals. The best options are a mixture of bleach and water, apple cider or white vinegar, a fast-acting spray, or Windex. Use an oil-based pesticide or spray if possible, as these are far more effective than water-based alternatives.

The limitation of DIY methods is that they only remove the eggs that you are specifically targeting. This is fine if you only have one or two egg sacs to deal with. But an infestation of more than a few egg sacs needs a professional exterminator.

What spiders live in New Jersey?

There are roughly 500 species of spider within the Garden State, so we can't go through all of them. Here’s a guide to identifying the eggs of the more common New Jersey species:

Triangulate House Spider egg sacs are loosely woven white spheres that measure roughly 5 to 6mm in diameter. They contain around 30 eggs.

Common House Spider egg sacs are brownish and have a flask-like shape. They are 6 to 9mm in diameter and contain around 250 eggs.

Wolf Spiders carry their egg sacs with them. If a wolf spider is carrying an egg sac, it will be a small, whitish ball about half an inch in diameter attached to the bottom of the spider's abdomen. When the spiderlings have hatched, they remain on their mother's abdomen until they are able to go off on their own.

Long-Bodied Cellar Spiders will also carry their eggs with them. They lay between 15 and 60 eggs and surround them with a thin sheet of silk. The eggs can be seen through the silk, making the egg sac look like an unripe blackberry.

Grass Spiders build their egg sacs by spinning a sheet of silk, depositing their eggs in the middle, wrapping them with more silk, and then placing another sheet over the wrapped ball of eggs. When finished, they have a flat-ish lens shape. They are around 25 mm in size, contain roughly 50 eggs, and can usually be found near the edges of a web next to the dead mother spider.

Orb Weaver egg sacs are round and can be up to 1 inch in diameter. Their color and shape vary according to the species of orb weaver. Most species lay 100 to 300 eggs in one egg sac.

Jumping Spider egg sacs are usually white and lens-shaped, and hold around 100 to 150 eggs. Similar to orb weavers, the egg sacs differ between species.

How to prevent spiders

Spiders eat insects and will travel wherever their food source goes, so the best way to keep spiders out is to keep insects away. Seal any gaps and cracks leading to the outdoors. Turn outdoor lights off at night, as insects are attracted to lights. Keep firewood piles and plants at least one foot away from the outside of your property. Shake out any items that have been outdoors before bringing them inside. It’s also worth shaking out items that have been in storage. Dust regularly and remove spider webs as soon as you find them. 

Frequently asked questions

Should I destroy a spider egg sac?
If it's inside your living space, yes. Get rid of it soon, before hundreds of spiderlings hatch from it. If the egg sac looks like it belongs to a black widow (whitish/grayish, a notch at the top) or brown recluse (off-white or tan, flat on the bottom), removal must be done by a professional.

What kills spider eggs instantly?
Bleach-and-water solution, vinegar, or an oil-based insecticide sprayed directly on the sac will kill the eggs on contact. A vacuum works just as well; just empty the canister outside straight away.

How long does it take for spider eggs to hatch?
Anywhere from 14 to 21 days for most species, though eggs may take longer in cold weather. Warmer indoor temperatures can speed that up, which is one reason an egg sac found inside shouldn't be left alone for long.

What month do spider eggs hatch?
In New Jersey, most spiders hatch between May and September. Exactly when depends on the species and when the eggs were laid, with spring layers hatching earliest.

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