I Found a Spider Egg Sac in My House, What Do I Do?

You were cleaning out a closet, or moving something that hadn’t been touched in a while, or maybe you just looked up at the wrong corner at the wrong time, and there it is. A small white or tan papery looking ball, maybe with some silk around it, tucked into a spot that was clearly undisturbed for a while. You know enough to know that’s not good, but you’re not sure exactly how not good it is or what you’re supposed to do about it.

What you’re looking at and what’s inside it

A spider egg sac is exactly what it sounds like, a silk casing that holds spider eggs, sometimes dozens of them and sometimes several hundred depending on the species. The spider that made it picked that spot deliberately, somewhere sheltered, out of the way, and close enough to where it’s been living and hunting. The sac protects the eggs until they’re ready to hatch, at which point you get a whole lot of very small spiders emerging from one spot all at once. That’s the part most people are picturing when they find one, and it’s a reasonable thing to want to avoid.

How do you know if it’s already hatched?

If the sac looks intact and is still round and firm, the eggs likely haven’t hatched yet. If it looks deflated, torn open, or you can see tiny spiders on or around it, they’ve already emerged. Finding a hatched sac doesn’t necessarily mean hundreds of spiders are now loose in your house, since a lot of spiderlings disperse quickly and many don’t survive, but it does mean you’re a little behind on the situation. An intact sac that you find before it hatches is actually the better scenario because you can deal with it before anything emerges.

What should you actually do with it?

Don’t squeeze it or crush it in place. That’s the instinct a lot of people have, and it’s understandable, but crushing an intact egg sac in a corner of your closet can rupture it and release the eggs or spiderlings right there, which is the opposite of what you want. The better move is to remove it carefully, either by using a vacuum to pull it loose and then immediately disposing of the bag, or by sealing it in a plastic bag and throwing it away outside. If you use a vacuum, don’t leave the bag sitting around inside the house afterward.

Where do you find them and what does that tell you?

Egg sacs show up in the same kinds of spots the spider itself preferred, dark undisturbed corners, inside closets, behind stored boxes, under furniture that doesn’t get moved often, in the garage, under the lip of shelving. Finding one in a spot like that tells you a spider was living and hunting in that area long enough to feel settled enough to lay eggs there. It’s a sign of more than just a passing visitor.

Does finding one mean there’s an infestation?

Not automatically, but it’s worth taking seriously. One egg sac means at least one spider was established enough in that spot to reproduce there. Depending on the species, that sac could contain anywhere from a few dozen to several hundred eggs. And if the conditions that allowed that spider to get comfortable, enough bugs to feed on, an undisturbed spot to hide, haven’t changed, there’s nothing stopping the same thing from happening again after this one is dealt with.

Does the type of spider matter for how you handle it?

It matters a little for how concerned you should be, but the removal process is the same regardless of species. Most egg sacs you find in Spring Hill homes belong to common house spiders, cellar spiders, or wolf spiders, none of which are dangerous. Brown widow egg sacs are distinctive enough that most people recognize them once they know what to look for, they have a spiky almost geometric surface rather than the smooth round look of most egg sacs. If what you found looks spiky or unusual, treat it with a little more caution and don’t handle it directly.

What about the spider that made it?

If you found the egg sac, the spider that laid it is likely still somewhere nearby. Females often stay close to their egg sacs, especially if the sac hasn’t hatched yet. So removing the sac without also dealing with the spider means the spider is still in the house and can lay another sac in the same or a nearby spot. Checking the area around where you found the sac for the spider itself is worth doing at the same time you remove it.

Should you be checking other spots in the house now?

Yes, especially the same types of spots, undisturbed corners, inside boxes that haven’t been moved in a while, under furniture, in the garage. If one spider got comfortable enough to lay eggs somewhere in the house, there’s a reasonable chance others have too in similar spots. Doing a sweep of those kinds of areas while you’re already thinking about it is more useful than waiting until you stumble across another one by accident.

What does this mean for the bigger picture?

Finding an egg sac is really a sign that whatever’s drawing spiders into the house and keeping them comfortable there hasn’t been dealt with yet. Bugs to feed on, undisturbed hiding spots, and easy access from outside are the three things that let a spider go from occasional visitor to established resident laying eggs. Dealing with the egg sac is the immediate step, but it doesn’t change any of those underlying conditions on its own.

If you found an egg sac and you’re not sure what else might be tucked away in the spots you haven’t checked yet, our spider inspection and treatment service can go through those areas, deal with what’s there, and address what’s been drawing spiders in so you’re not finding another one in a few months.