Rats In Cages, Edit #2

[Achebe]

1. There are rats in cages and mazes that are happier than I am.
   
2. They do not count walls and stars.
   
3. They do not think of life and death or dark and light colors.
   
4. I watch them, fur and flesh over bone and brain.
   
5. I give them levers to pull, to see if they decide.
   
6. The levers move in silence.
   
7. It is a chemical, and a muscle.
   
8. It is computable, and yet chaotic.
   
9. Though in vain, I believe it is noble.
   
10. They shake in self-awareness at the product of their hands.
    
11. In reflection they see their fur
    
12. Placed over skin that is not their own
    
13. Just before the glass breaks.
    

1) - don't see the need for 'cages and mazes', since no rat lives in a maze. 'There are rats in cages happier than I' is less wordy, though prosaic. Up to you.
2) - do you count walls? why would counting stars make you unhappy? It's not related to the line above
3) - One too many 'they do not' - it's reading like dull prose. That rats don't think of life and death is not worthy of mention. 
4) - passable line
7) - What is 'it'?
8) - One too many 'it is' es
9) - A supremely frustrating line. What is this about? Some stupid rat has pulled a lever that's cracked open a bottle of cyanide? Why is that noble? Is it noble because the rat is sacrificing itself for your PhD thesis? The rat doesn't even know what a PhD thesis is. For me, this is the nadir of the poem
11- 13) - I have stopped reading at this point.