Hunter, in Darkness - Hint Needed (SPOILERS up to what I believe is the final puzzle)

I’m catching up with this recent IFComp entry from (ahem) 21 years ago, and I seem to be at an impasse. There are solutions and walkthroughs available for this game as well as the source code, but those would probably give away the answer outright, whereas I can’t help hoping that a gentle nudge in the right direction will be sufficient here.

I’ve gotten to the part where you confront the Wumpus at the base of the canyon. I’ve found several ways to get to this spot - you can shoot the Wumpus at the beginning of the game or later, you can climb downwards or travel by bat - but all of them seem to end up in the same place: you’re at the bottom of the canyon with an injured arm. If you go forward, you find the Wumpus prepared to shoot you with your own crossbow.

I’ve noticed that the bats are maddened by the smell of your blood, and if you take off your bandage, wait a few turns, and then go into the Wumpus’s presence, the swarm will attack the Wumpus. However, this always ends with the Wumpus fighting through the swarm and killing me, whether I retreat or not.

I’ve tried communicating with the Wumpus - talking to it, giving it things, surrendering, attacking, weeping, shouting. This route seems unpromising.

I’ve noticed the crevice at the base of the canyon with the rushing stream within. However, there’s no obvious way to use it, unless you’re only looking for a less painful method of suicide than the Wumpus’s claws. You die if you try to climb down it, and the Wumpus simply steps over it.

I still suspect the solution involves the bloodthirsty bats. However, if so, I’m somehow missing the trick to using them properly. I’m probably missing something quite obvious. Would anyone be kind enough to drop a hint here?