Carolina Gardening: Ferny weed with little pink flowers, need ID!, 0 by thea611

thea611 wrote:
I was unable to get very good photos of this plant, but hope maybe someone can ID it. I walk dogs at our animal shelter along a path thru a meadow and the woods, and have found caterpillars on the plants recently, and it might be easier id'ing the caterpillars if I know what plant is hosting them. It's a tall plant (some 5' and more) with one main stem up the middle, and ferny foliage on long arms all the way up. Right now it's got small pink flowers. Can anyone id it from these terrible photos?