I forgot to post this photo and I find it interesting. These caterpillers form a web around leaves on a tree and they eat everything inside. The webs are strong and wind nor water bother them. Trimming the branches is about the only way to get rid of them. (No, I'm not going to suggest that to Jack or he'll be climbing trees just to trim the branches!)
We really had an infestation of them this year as they settled in the madrone trees.