So we know Drillers are vital to the game- they attack and sieze and they can be sent deep into the ground to create a mine and get dat precious N-(aparently with less efficiency everytime)
But what do they look like?
I assume because they can be manufactured at factories, they are machines... and they can also be stolen by thieves.

So are they just little bots with drills on em? Are they dudes operating mecs? Are they actually sea cucumbers taken from the bottom of the ocean and enhanced with drill like prosthetic?

What do you think one looks like?

I'm currently on mobile so can't conveniently search, but there is already a topic on this. Could be hard to figure out the search terms that would get the proper result though.

Here's an old thread: viewtopic.php?f=10&t=901&hilit=what+are+drillers
And another in which people made up some lore and I calculated the surface area of the world of Subterfuge: viewtopic.php?f=5&t=1111&hilit=Europa

Whatever they are, thet might be amphibious. Assuming the shields are the protective bubbles in the outpost diagrams, and some of the drillers are consumed destroying the shields to get in to fight the outpost's guards, then maybe the "shield fighting" drillers are released from a sub into the ocean before the sub can enter an outpost. We can then assume they can swim and their weapons work underwater.