These guys are everywhere this morning Are they good guys or bad? ( photo / image / picture from Donna S's Garden )
Those look like Webworms click on blue link for more info. Do a google search to make sure and then work on getting rid of them. They spin webs on tree branches then strip them of leaves. The web is to protect them from predators but if you find any on your trees you can take a stick to break open the web then either spray them or let wasps feast on them.
Those guys will never be butterflies! Toni is right--webworms--and I speak from experience. Ghastly critters, but the hens like them!