Roosters crow at any time of the day, not just in the morning. Sometimes, roosters crow as a warning because of the invasion of other animals, the declaration of territory or the threat of other roosters. However, when nothing happens, they do bark the most in the morning.
For many years, scientists believe that the rooster crows in the morning because the light changes from dark to bright after the sun rises, and the rooster responds to the stimulation of light. But some people think that the rooster is not stimulated by light, but crows until dawn. In other words, the rooster has a concept of time and will ring like an alarm clock in the morning.
Principle of rooster vocal system;
The same chicken, rooster and hen will make completely different sounds. In comparison, hens only giggle, while cocks' voices are loud and clear. This is because their vocal organs are different. The vocal organs of human beings are vocal cords, and the vocal organs of chickens are sound tubes.
The vocal tube is the vocal organ of birds, which is mainly composed of vocal bones and vocal membranes, like some birds that can make euphemistic calls and vocal muscles, but chickens have no vocal muscles. There is no difference in the composition of horns between hens and cocks. The cock's singing membrane is obviously thinner than that of the hen, so when it vibrates, the cock's singing membrane makes a clearer sound, while the hen's is much lower.