I don't even think the mountain tiles make any difference. I had one appear pretty deep. It doesn't help that these bugs are pretty tough, I sent one of my tamed bears in there and they tore him apart in seconds, I don't even want to think about what could've happened to a colonist without a good personal shield.
My current strategy to deal with them is to just turn whatever room they spawned in into an oven with some Molotov and then restrict the area so that my colonist don't run in like idiots trying to put out the fire. The down side to this is that the whole room the bugs infested will be burnt down and will need to be rebuilt, this is especially bad if they infest an important room like a stockpile. This also doesn't work too well with wooden walls.
Pic related is one said infestation, thankfully it was just a room in expansion so I didn't lose anything except my brave bear.
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My current strategy to deal with them is to just turn whatever room they spawned in into an oven with some Molotov and then restrict the area so that my colonist don't run in like idiots trying to put out the fire. The down side to this is that the whole room the bugs infested will be burnt down and will need to be rebuilt, this is especially bad if they infest an important room like a stockpile. This also doesn't work too well with wooden walls.
Pic related is one said infestation, thankfully it was just a room in expansion so I didn't lose anything except my brave bear.
[attachment deleted by admin - too old]