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
And it will keep on running and twitchingWhen everything seems planned out
When everything seems nicely planned out
Well the human race will come and smack your faceHow come all my body parts so nicely fit together?
All my organs doing their jobs, no help from me, noA person pulls a spider's leg out
To watch it keep on moving and twitchingWhen everything seems planned out
When everything seems nicely planned out
Well the human race will come and smack your faceSatan lives here
On grain and earth, rain and airHow come I just smoke and smoke and smoke
And curse every butt I spit out?
All night long I grind my teeth and I wake up when I coughYou can put me in and iron lung
And I will keep on breathing and twitchingWhen everything seems planned out
When everything seems nicely planned out
Well the human race will come and smack your face
You might be dead, but you keep your head