I only know because one day wihile sitting on toilet looking out the window I saw a dobber carry a bug into a mud hut. Flew away and within minutes came back with another.
After I finished my business I opened the window and broke open the hut. It was packed full of spider carcasses and had a single larvae inside. I waited for the dobber to come back and zapped it with spray.
Later that week I was tending my garden and noticed a hornet subdueing a spider. He picked it up and flew it drunkingly back to it's nest buried deep in a thicket of creeping juniper.
Within a week the thicket of juniper was gone.
Bee's I can handle and even appreciate. Wasps, hornets, dobbers, need to find someone elses gardens to live in.
Wasps eat potential garden pests including the venomous black widow spider. Adult wasps eat only pollen and nectar (or your soda at picnics). They only hunt for meat (insects, worms, your barbequed hamburgers) to feed their larvae. Wasps nests have only one purpose: to ensure the production of young. At the end of the nest’s cycle, every member of the nest, except emerging queens, dies.