Originally posted by Yakumo_2020:

Then I use an Abysall harpoon to put a Troll in it. Contains the danger and keeps another Trolls from spawning in the same general area.

This was an unintended bonus when I set up my base at the Trader. We woke up one morning to hear the low growls and grumbles of a Troll, and were frantic that it would destroy our base. When we found that he'd stumbled in one of our pits, we left him there for entertainment value. Only later did we realize that his presence kept other trolls from spawning in.