Worthington Ohio real estate


Everything you always wanted to know about cobwebs

Everything you wanted to know about cobwebs but were afraid to ask was originally published by home inspector Jay Markanich as "cobwebs." 

Great time of year for the truth about cobwebs. I did not know a lot of this. I did not know about the connection with "moving air."   As real estate agents we walk through spider webs in vacant homes and basements occasionally, but I sure don't envy a home inspectors more intimate knowledge of spiders and creepy crawley things.  

Without further ado: Cobwebs

What are cobwebs?  And why do they appear in houses?  What does a multiplicity of cobwebs mean?

As regards cobwebs, the word cob has nothing to do with corn!  It probably originated with an Old English word - "COPPE," which meant spider.  So the word "cobweb" might just be a sloppy way of saying coppweb.

Cobwebs look like hanging clumps of silky spider web material.  That's what they are!  They are what is left after a spider abandons a web.  It may be that the spider sabotages a couple of the structural, hanging points of the web so no other interloper can take advantage of the web being abandoned. 

What kinds of spiders produce cobwebs?  Are there "cobweb spiders?"  Yes, and they make up the family Theridiidae.  One of the most common house spider in the United States is Achaearanea tepidariorum, of this family.  The infamous Black Widow spider, Latrodectus mactans, also belongs to this family.

On the particular inspection in the photos above I encountered a number of black widow spiders and what looked like their egg sacks. 

Some cobwebs may not be a part of a previous web at all.  They may instead be a purposeful, hanging clump of silky web material intended to safely house many egg sacks.  Other insects will not bother the eggs as they know what will happen to them in the web!

As they hang there, over time and in the blowing air current, the cobwebs gather dust and become more and more visible.

What does a multiplicity of cobwebs mean?

Simply that the location is a habitat that can support many spiders!

Spiders need moisture, which they can always go outside to obtain, and a food source.

The larger the food source the more abundant the spider population will become!

This house was unkempt, to say the very least, and therefore full, and I mean FULL, of roaches.  It also had a serious termite infestation.

If spiders are well fed, their basic objective in life is to do what all fauna do, make more spiders!

And as the habitat provides more and more opportunity, the spider population will increase.

Spiders build webs near moving air.  They do that instinctively.  If the air is moving it is hoped an insect will fly by.  The web is built to capture as much of the air current as possible, in the continued hopes that it will capture food.

If the web comes up empty for a period of time, it will be abandoned.  And maybe partially dismantled.

However, if another spider senses that this is a good place for a web, it will ignore the fact that a previous web was made and build a new one. 

That one might be abandoned as well, and the cycle continues.  Eventually there is a multiplicity of cobwebs, getting dirtier and dirtier with floating dust, and more and more visible.

Of course, if the food is crawling by that is good too!  And I can confidently say that a LOT of food was crawling by in this house!

My recommendation:  when you see a cobweb you know there is a moving air source that encouraged a spider web.  A web can be built quickly, even overnight, and you might not even see it until it is abandoned and begins to collect dust.  However, you may want to investigate the reason for its placement.  There is moving air nearby!  That moving air may be because an HVAC register is blowing air in that direction, but it may also be a gap in the exterior skin or around a window or door that should be sealed for energy efficiency also.



Jay Markanich Real Estate Inspections, LLC

Based in Bristow, serving all of Northern Virginia



This post provided by Maureen McCabe HER Realtors*

Contact Maureen McCabe of HER Realtors* - 614.388.8249

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Information is deemed to be accurate but should be verified to your satisfaction.  Information provided herein is supplied by several sources and is subject to change without notice.  Opinions expressed are solely those of Maureen McCabe.



Comment balloon 8 commentsMaureen McCabe • October 05 2011 05:27AM


I have to say, Maureen, that was quite the inspection, in lots of ways.  And thanks for the reblog!


Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) almost 8 years ago

That is really a sad story about the home inspection and the whole situation.  The roaches part really makes my skin crawl. 

I never knew for sure there was a spider involved in all cobwebs...  of course there would be. Back when I was watching 'The Munsters' on TV as a kid I remember being in a silo at my grandpa's farm and wondering if cobwebs came from corn cobs... or silage.  So many cobwebs up above.  



Posted by Maureen McCabe, Columbus Ohio Real Estate (HER Realtors) almost 8 years ago

I found Jay's article fascinating.  Good reading throughout.

Posted by Lenn Harley, Real Estate Broker - Virginia & Maryland (Lenn Harley, Homefinders.com, MD & VA Homes and Real Estate) almost 8 years ago

I love it.   A mini animal kingdom documentary on a part of everyday life.

Posted by Maureen McCabe, Columbus Ohio Real Estate (HER Realtors) almost 8 years ago

Interesting information. I never really thought much about spider webs - other than avoid them!

Posted by Gary L. Waters Broker Associate, Bucci Realty, Fifteen Years Experience in Brevard County (Bucci Realty, Inc.) almost 8 years ago

Great information Jay and Maureen great job on re-posting this blog.  It is full of interesting information.   Pictures.. freak me out a little as I hate spiders....

Posted by Stephanie Stringer, Mortgage Loan Originator (First Choice Loan Services NMLS#210764) almost 8 years ago


Thanks-  this was very interesting I just  learn a few thing about the what the presence of spiders may mean. Dampness and air flow - possible gaps in the property.  Thanks for sharing.

Posted by Michele Cadogan-Cell 917-861-9166, Licensed Real Estate Associate Broker - (Fillmore Real Estate 2990 Av U, Bklyn , NY 11229) almost 8 years ago

Thanks all.  I hate spiders.  A friend got bit by a brown recluse spider about 18 months ago. 

Posted by Maureen McCabe, Columbus Ohio Real Estate (HER Realtors) almost 8 years ago