Backyard Biology

Nature stories from my backyard and beyond

Nature Activities

Dusting for Spiderwebs

Tuesday, August 11, 2009

f you have spent much time walking through the woods, chances are at one time or another you have walked into a spider web. The threads of many spiders, especially small spiders, are so fine that they are almost invisible and will go unnoticed unless there is something sticking to it. That something could be an insect, dust or drops of water. For this reason, we notice many more spider webs on a cool moist morning when the dew coats everything including the spider webs. At these times, we may notice a web on the grass every few feet while they will seem to disappear a little later in the day when the dew has evaporated.
I am always amazed to hear when people are surprised to learn that cobwebs are caused by spiders and not dust. Cobwebs are the webs made by a particular type of spider - cobweb spiders of course - that are pretty much invisible until they are coated with a fine layer of dust. Well, if a coating of dust makes a cobweb visible, then it should make pretty much any web visible. So if you want to see the structure of a web, why not dust it? This will not only allow you to see the web, it will also make it possible to photograph the web.
Spider webs come in a great variety. There are cob webs, sheet webs, orb webs, ray webs, funnel webs and many others. Dusting them brings out their unique structure.
Pretty much any book on spiders will have a section on their webs with accompanying diagrams. My favorite spider web diagrams are from the book, “How To Know the Spiders”, a Pictured Key Nature Series book. It is out of print as far as I know, but used copies can be purchased from Amazon. Below is a diagram from the book of a Bowl and Doily spider.bowl and doily spider diagram image









  1. Find and old sock that doesn’t have any obvious holes in it.
  2. Fill the bottom third of the sock with Cream of Wheat, flour or some other fine powder. Tie off the sock right above the powder.

Find a spider web that you wish to dust. Hold the sock just upwind of the web and tap the sock lightly. The powder will come out of the sock and cover the web.web before dusting








web after dusting imageWhen I’m not using my sock, I keep it in a bread wrapper to prevent the dust from getting all over everything and to keep it dry.