Where you can dive into the dark canal in mycopolis, i notice that there are spawns there that will more than likely see you as soon as you transition. This should be changed perhaps?
Dive into Dark Canal
The creatures cannot spot people from their spawn point but it does happen when people go down that they lead them closer to the steps and such. Which is another issue in itself.
I have been down there when there was nothing there, then reentered and found a gelatinous cube right on top of the spawn - I was paralyzed before I could issue a command. Something's happening there.
Cubes look really bizarre on those stairs.