You could try and select them in scene view (when running) to see what game object they are. If they should be following you then they'll likely have
ObjectFollower on them, if that's the case I'd check if it's there and if it's not disabled (or it's child game objects).
I'm not sure if that's the intention for this tutorial as I've not followed it. Another approach would be to download example Farm scene and see how it's set up there. While those tutorials might get out-of-date I've found example scene to be great source for all kinds of interactions.