In fact, the scientific statement is:
It is not easy for a hen to lay an egg. It takes at least 10 minutes for a hen to lay an egg, and even four or five hours for a long time. Hens that are about to lay eggs are very alert. When people or other animals approach them, they often hide quickly, or stand up their hair, or even peck people with their mouths. After everything was quiet, the hen quietly hid and laid an egg with all her strength. It takes a lot of energy for a hen to lay an egg.
After laying eggs, the hen takes a rest, and when her physical strength is almost recovered, she leaves the laying box very happily, and then cackles loudly, which on the one hand shows the hen's joy, and on the other hand, informs her partner rooster to share its happiness.
Therefore, when we hear the hen cackling, we can rush to the hen's nest to see if there is a fresh egg. At the same time, we will also find that there is a rooster as happy as a hen.