A noise

poem about one of those noises you hear as you try to fall asleep,cant figure out

The clock is ticking,my heart beats fast.
A noise in the dark comes sweeping past.
My heart starts to flutter,
My breath comes quick.
Oh I feel I might be sick.
My eyes flash around hoping to find
The source of the noise
that crept in my mind
Is it the wind or a loose shudder?
Maybe a mouse snacking on butter
So i'll go to sleep I do not care
About a noise that came out of nowhere.