Not so long ago there was many animals that roamed the earth. All over there were deer, squirrels, and every type of bird you could imagine. But that all changed.
The change did not happen all at once. But gradually trees were cut down to build office space, habitats were destroyed for a parking lot, and slowly the animals disappeared
Now the animals are hard to find, and some of them are gone forever, never to be seen again. It is hard to find green space or a forest. So if you do see one, cherish that time when you can feel free and happy. Not everyone will be able to know that feeling.