Factorio Forums

I just got the achievement out of the blue. I'm not generating enough pollution that the cloud covers any biter nests. I'm not getting any alerts.

Should I be worried?

You won't get any alerts until there are biters/spitters attacking your base/defenses.

Are you sure the pollution cloud doesn't reach any enemy nests? If it borders on black (uncharted) areas there might be an enemy nest hiding behind absorbing the pollution. If it's been a long time your radar scanned a particular chunk then biters may have created a new nest there in the meantime.

Come to think of it, I actually removed my radars while I was redoing some belt networks. I'm going to put them back and see what happens.

Update: I started getting attacks soon after this. I've not yet discovered any new nests.