Animals must be able to respond to stimuli in the outside world through their senses. If they are not able to process stimuli, then their quality of life is diminished, and they may not even be able to survive. The 12th chapter concludes with a call to action. Yong uses anaphora—the repetition of initial words or phrases, specifically “we should” in the following passage—to increase the intensity and pacing of his plea to stop desecrating sensory environments:

We should approach this work humbly, recognizing how easily our intuitions lead us astray. We should move forward hopefully, knowing that even a partially successful attempt will reveal wonders that were previously hidden to us. And we should act quickly, knowing that our time is running out (334).

What follows in the final chapter is Yong’s investigation of the sensory pollution—specifically light and sound pollution—that prevents animals from being able to function fully within their umwelten. Humans, too, are negatively affected by this pollution.

While light and sound pollution are the result of an excess amount of stimuli being put out into the environment by humans, Yong earlier describes the sensory losses that are the result of stimuli being removed from the environment by humans.