We used the Pavlovian approach while working in the run: a shovel banged against the wheelbarrow. The hens knew from "chickhood" that meant DIGGING, and DIGGING meant WORMS, BUGS, SPIDERS, and other tasty treats as we turned the soil. Several competed with each other to "ride the shovel" to be first in line when the next spadeful of dirt was turned over.
As long as the shovel was there, surprisingly, none of them ever struggled when we picked them up.

As long as the shovel was there, surprisingly, none of them ever struggled when we picked them up.