Try the term "frass" instead of scat and your search will work:
https://www.bing.com/images/search?v...h=497&expw=640
The best way to get them to stop eating quickly is to find them ( by looking for frass or where they're eating ) and just pick them off by hand. They can do a lot of damage, fast. If they have the white wasp eggs sticking out though, let them be! You'll be glad you did, next year.
Good luck!