There are three reasons:
1. The Forbidden City was guarded by a large number of troops in ancient times, and places with a serious atmosphere are dangerous places for sensitive birds
In ancient times, the Forbidden City was the place where the emperor lived. It was a very sacred and serious place that generally did not allow people to play casually. And for the safety of the royal family, there are a large number of guards in the open and dark around the palace, and these guards can be said to be the most elite part of the empire, and they are all people who have been baptized in blood and fire.
A person's temperament will become very different after being baptized by a cruel war. Although ordinary people can't say there is any difference, they can feel it and stay away from this kind of "dangerous" group of people. . For birds, this group of people is even more dangerous. Animals are much more sensitive to the environment than humans. For example, cats and dogs are very sensitive to earthquakes.
Similarly, birds are also very sensitive to the perception of their living environment. These large numbers of people who have been trained or baptized by war, when gathered together, are very dangerous to the birds. Their instinct is to Won't go near these places.
2. In the early stages of construction, the roofs of the Forbidden City were all painted with special-tasting paint
The palace is such a sacred place, so naturally birds are not allowed to poop on the emperor's head, so In the early days of building the palace, our country's skilled craftsmen had already thought about this problem. They mixed some special materials that are irritating to birds but insensitive to humans into the paint, and then painted them around the roof and walls. These houses would then emit an odor that was offensive to the birds, keeping them away from the palace.
3. Most of the roofs of the Forbidden City adopt a "sleek" structure
If you look carefully, you will find that the bricks and tiles on the roof of the Forbidden City are all arc-shaped, and the curvature is very large. This structure makes it impossible for birds to gain a foothold on the roof. Everyone knows that when birds stand, they do not rely on their claws to prop themselves up on tree trunks. Instead, they rely on their claws to grasp the trunk to stay steady. The roof of the Forbidden City adopts a smooth and curved structure, which makes it impossible for birds to get their claws down, so birds cannot gain a foothold on the roof.