My rambles in shambles

It can never stay still
Not even for a second
I need to have my weapon
With me at all times

Why is it always a battle?
I told you to have an open eye
Everyplace a place to die
When your here with frightened foot

You cannot stay here in the nest
You must be the master of probability
The leading doctor of psycho numericy
Not just the president of pi

Do not dismiss that crack or creak
See all things there is to see
Everyplace an enemy
Could be on the prowl so Listen for every sound