I listened carefully, but didn’t hear a response after I’d thumped, so I resumed my digging. Maybe the other creature had fled, afraid to face me. The barrier at the entrance of the cave blocked any possibility of my spotting this intruder.
I froze when I heard another thump, this one as loud as the last. Without hesitation I thumped back. It’s important in these situations to reply as quickly as possible. She who thumps last wins! We continued the contest for several more thumps, after which the other creature must have gotten the hint and retreated. After a long period with no thumps from the enemy, I rejoiced. I’d thumped last! I’d won the battle!