Octopus is a kind of marine animal that we are familiar with. In the course of studying them, researchers have discovered many interesting phenomena. For example, octopus can change color, and it can change more than one color. When octopuses are in danger, they will run away for the first time; But when they don't have time to run or hide, they change color to mislead their enemies. In addition, when octopuses are hunting, they also change color, in order to make their body color blend with the surrounding environment, so that prey can not notice them, so that they are more likely to succeed in hunting.
Under the skin of octopus, there are many pigment cells, which are not the same color, but different colors. Moreover, these pigment cells also contain some expanders, which means that octopuses change color very quickly, which makes them better able to protect themselves and prey more easily.
We might normally think that octopuses don't make calls. In fact, octopuses make sounds, and they make more than one kind of sound. For example, when they eat, because of their hard mouth, they tend to make loud sounds when they eat, just like the sound of a file at work. For example, when the octopus spouts water, it makes a popping sound; Similarly, octopuses make similar sounds when they swim forward faster. Octopuses can make a lot of sounds, but this may not be called a call.
