Part of the strength of A Midsummer Night's Dream is that we're not always sure where humans and the natural world, as two separate elements, fall in relation to each other. Sometimes humans are part of the natural world, and complemented by it, like women becoming fertile with the midsummer fest, or crops that agree with seasons to put food on the table. Other times the natural world seems alien to man because he has separated himself from it – especially with his urban life. Some Athenian workers want to rehearse a play in the woods to escape the city distractions, but all the sprite Puck needs to do to frighten them from their wits is to pretend he's a regular woodland creature or element – a fire, hound, or bear. Even at the end of their tough evening, the four young lovers, who have a lot to escape, decide to go back to Athens. Regardless of all the drama in the city, their courtly beds are no doubt better than this dirty forest floor. In this way, the natural world is an escape for man, but it's also a reminder of how good man has it in his other home.
When the Athenian lovers are in the forest, they aren't bound by courtly rules and therefore can pursue their urges as they desire. Unlike the city, the natural world is a free space, one that allows man to have his natural feelings without bottling them up or bureaucratizing them.
The natural world is a tumultuous place of hedonism and madness. The youth and the Mechanicals are enchanted and manipulated by the forest creatures and their only hope of returning to safety and sanity is in heading back to Athens.