I was walking in the woods today. I did not see deer when I went in. I heard birds. I heard squirrels. I heard people and dogs. It was a wood-without-deer.
Coming home, along the path, there were deer in front of me. Eight deer. Suddenly it was a wood-with-deer.
The wood did not change because suddenly deer were in it. The wood changed because suddenly I was aware deer were in it.