Species invasions are actually a very common occurrence on a global scale. Although there are countless species of organisms on the planet, these are distributed all over the world, with some species being endemic to certain areas and not present in others, and others having a relatively wide distribution. When some species appear in places where they would not have previously existed, this is when the species may become invasive.

Under human domestication, people are more like the head wolf of the pack in the eyes of dogs, and when people are alive, they are absolutely loyal. However, when the "head wolf" dies, this obedience disappears, so there is no difference between the human corpse and the meat of animals in nature in front of the dogs

It happens to be the season when mosquitoes and flies go wild, but it is true that there are not as many flies as there are mosquitoes today. This has a lot to do with our improved sanitation today, after all, flies need to lay their eggs on manure pits and rotting food, while many rural toilets have now been converted to squatting, and the shorter disposal cycle for waste has greatly reduced their hatching.