Both. It's both. Goblins followed your woodcutter drudges back.

The smelter has just finished and your Builder Drudges have just gone back inside when you see your Woodcutter Drudges hurrying towards the tower. This is far earlier then expected, and their packs don't look as full as you'd have expected. Which means trouble. Not necessarily much, your Drudges had been set to prioritize survival over resources so they'd have retreated at the first sign of hostiles, even ones they could defeat. A small amount of resources that you gain multiple times, indefinitely, was better then a medium amount of resources once.

Of course, you muse as you shade your eyes and peer past your returning drudges, that sometimes means that hostiles are lead to your home. In this case a set of four... five... eight goblins. Right. Good news, they're goblins. And probably low level ones. The bad news is that there were eight of the damn things. Sufficient numbers could and would tell. Your walking corpses were... only about on par with a goblin, based on your experience. Maybe a little better, given they were immune to a lot of the dirty tricks goblins liked to use- poison, cut tendons, gang tactics to enable shots at vital organs... All things undead just didn't care about. Well, the gang tactics were mildly problematic, but that was merely from numbers, not vital organs. Still, that's... a digression. You pull yourself back to the present, thankfully well before the goblins arrive.

You wave the Woodcutter Drudges inside, then duck inside yourself and close the door. That should buy you a little bit of time to get everything as set up as it can be. The Walking Corpses stop their semi-aimless wandering and take up ambush positions, while your drudges hurry to the storage room to drop off their loads, and you raise an eyebrow at the alert that pops up. Five lumber each, eh? Looks like they got interrupted fairly early, then. The Goblins are probably looking for you, based on that. If they weren't before, they probably are now. The sort of squad they deploy isn't something that just gets deployed on a whim. Not in this area. Not when that many goblins could overrun a hamlets guards and make off with some of their livestock.

So, you're facing what's more or less a decent raid attempt by the local goblin tribe. And, of course, you can't let this challenge go unanswered, if you survive this. To do such would be little more then an admission of weakness. Your musing is cut off as the door swings open, and you peg the first goblin through with a Chill Ray. They keel over, having turned a familiar frostbitten black, but three more push through and your walking corpses step forwards and begin to pound on the goblins. So far, so good.