when looking to the ground from e.g. inside a building with a shovel in your hand the game offers me the "dig for worms" option.
the example shows how the option is visible while looking outside a window with the cursor pointing to the ground. it also vanishes when moving the cursor away from the ground.

see imgur:
https://imgur.com/a/BPy5IbN

it is also possible to perform the action, i could however so far not retrieve worms from the wooden floor i was standing on..