Tent Caterpillars

We've got Garden Articles for Western WA on another website for Shelton Land & Homes, LLC. This article caught my attention today, because there was a caterpillar that looked a little bit like this one crawling up my house along side the front door.  Here is the article:

Tent Caterpillars Rarely Kill Trees
Tent caterpillar infestations are being reported throughout our coastal area. They are easy to notice with their unsightly tents and defoliation of deciduous trees. These notorious caterpillars attack a wide variety of plants including alder, apple, ash, birch, cherry, cottonwood, willow, fruit trees, and roses. During heavy infestations the caterpillars will migrate and feed on many other plants.
Early in their development, tent caterpillars tend to eat all of the leaves on one branch before moving on to the next. Later, they split into smaller groups and attack several branches. A single tent may result in 20% defoliation of a small tree.(read more here.)