In fact, the earth's crust itself is a natural source of minerals, many soil and rocks contain a certain amount of salt, careful observation of cattle and sheep should know, cattle and sheep in the grass, but also often "eat soil" or lick the stone, they do so, in fact, the purpose is to obtain the salt

This phenomenon could not be detected through traditional dietary research methods, but by using DNA-based techniques, such interactions were revealed for the first time, leading to important questions about how human activities affect wildlife.

When we humans feel very tired, we often say that we can fall asleep standing up, but this is just a description. In reality, it is impossible for humans to sleep standing up, but there are many animals in nature that have this such a skill that humans do not have, for example, horses can sleep standing up effortlessly.