jonesandbennett:

One Nostril: I’m cool

Other Nostril: They have taken the bridge and the second hall. We have barred the gates but cannot hold them for long. The ground shakes, drums… drums in the deep. We cannot get out. A shadow lurks in the dark. We can not get out… they are coming.

Because the duplication of nostrils, like the duplication of other critical parts like lungs and kidneys, raises the likelihood that even if one has its capacity degraded the other one still works. Oxygen intake is so critical and vulnerable we can mouth-breathe too, but this is literally the point.