Ask what's going on.

Quest Text How can I help you?
If there is something you need, I'll sell it to you at high price.

Summary All he talks about is making more money.
Doesn't he understand that our necks are literally on the line? Tsk tsk...
But who can I blame? It's my fault for trusting Dustin NPC Knowledge, that coward,
and his persuasive words to join him to earn easy money on Iliya Island.

Summary According to his journal,
these critters never displayed any signs of aggressive behavior...
And yet, the moment they see us,
they rush in with seemingly murderous intent.
So we're stuck here,
unable to investigate the true cause of whatever it is that is making those sounds...
It's literally driving us up the wall.

Summary Don't start, Dustin NPC Knowledge!
You ought to be ashamed of yourself, you big lug!
I believe it was only hungry for some Paste Bait NPC Knowledge Item...
*clears throat* Hahaha!
Anyway, now that we found the reason,
we can finally get some well-deserved shuteye!

Summary What's with the look? Business is business.
No use staring. You won't squeeze any money from me.