What would happen if humans suddenly disappeared?
This was the first theory of the doomsday world when the apocalypse began is 60% of humans have disappeared from the World.
It means that humans can no longer roam around freely nor they can do their duties properly they can only live in pit holes and wait for their deaths.
It literally means they have disappeared, only a few individuals killed the creatures and made their way to the top of the food chain.
Even if the few individuals are strong and can move around freely they can't maintain the whole earth that has been preserved and developed by billions of people.
Humans disappearing for a week. Food began to rot, and pets and zoo animals began to escape and roam the streets.
Humans disappearing for a month. Without human intervention, the nuclear power plant reactors would go out of control and cause devastating damage to nearby lives.