How Does A Duck Know?

How does a duck know what direction south is?
And how to tell his wife from all the other ducks?
You can cut a chicken's head off
But it will keep on running and twitching
When everything seems planned out
When everything seems nicely planned out
Will the human race come and smack your face
How come all my body parts so nicely fit together?
All my organs doing their jobs, no help from me!
A person pulls a spider's leg out
To watch it keep on moving and twitching
Satan lives here: on grain and earth, rain and air
How come I just smoke and smoke and smoke and curse every butt Ispit out?
All night long I grind my teeth and I wake up when I cough
You can put me in an iron lung
And I will keep on breathing and twitching