Boogers. There. I said it. Now you are all thinking about thoseooey gooey slimy’s that drip from our noses when we are sick. But our bodies produce mucus every day—it helps protect our lungs by capturing dust and dirt when we inhale. Mucus production ins’t only a human process, however. Lots of different animals produce mucus for a variety of different reasons. Take these Catalina ocean dwellers, for instance:
At night this fish may produce a mucus cocoon around its body. This inhibits predators from using their sense of smell to find these fish while they are resting.
For more on this species: https://www.montereybayaquarium.org/animal-guide/fishes/california-sheephead
As a defense the sea hare can produce a purple ink and something called opaline. This slimy, sticky secretion was studied a few years ago. It is believed to interfere with a predator’s ability to taste and smell.
For more on this species: https://blogs.scientificamerican.com/running-ponies/sea-hares-thwart-spiny-lobster-attack-with-goo/
The slimiest of them all. Pacific hagfish create slime as a defense against predators. Their slippery bodies allow them to flee from the mouths of predators and slip into tiny crevices.
For more on this species: https://news.nationalgeographic.com/2017/03/hagfish-oceans-slime-deep-weird/