If you put a battery in a socket adjacent to a drill, then drive the worm over to the rocks (so that the drill is beside the rocks), it should mine it!
Thank you so much for trying the game! Definitely a bit of DUNE inspiration with the worm!
Bug spawning was something we never quite had a handle on, so it feels a bit random whether or not you start a successful run. The shop is randomized so getting a bunch of worm turrets early usually is the best strategy, but I digress.