Grasshoppers sometimes "spit" brown liquid to defend themselves.
If you've handled enough grasshoppers in your day, you've probably had a few spit brown liquid on you in protest. Scientists believe this behavior is a means of self-defense, and that the liquid helps them repel predators. Some people say grasshoppers spit "tobacco juice," probably because grasshoppers have been associated with tobacco crops in the past. Rest assured, though, the grasshoppers aren't using you for a spittoon.
Now I can sleep at night knowing this fact, how about you? 