Supposedly they do. Haven't had a tomato hornworm in years. With all the rain this year we had so many bugs it would have taken an army of guineas to keep up with them. They aren't supposed to bother the plants but I actually caught them eating my raspberries, pecking at the tomatoes and peppers. This is second generation and I never had that problem with first generation. It's very frustrating.
Before they made the huge run for the chickens they were the ones always ruining my garden. I finally told my son I wasn't going to garden anymore unless they confined the chickens. Then there were those few that jumped the fence. Clipped their wings, they still got out. Turned out there was a platform they were jumping on to get over the fence. Finally got that resolved and now the guineas are misbehaving! Arghhhh!
Guineas do like to take their dust baths in freshly tilled and planted areas to. I finally learned to mulch right away to keep them from digging my newly planed rows.
They are good watchdogs though. can be very loud. And they're kinda ugly. Feathers are pretty (we have pearls), but they have ugly faces.
