Fruit fly

A little small fly
I think the call it a fruit fly
It's here by my side
That I cannot deny
It buzzes by so slow
It annoys me oh so
When you smack it goes go
It's just one small creature
But it's the main feature
I would have a ruler
If I were a teacher
And when I'm busy
It's flying around
Going into a frenzy
I want to knock it down
THERE it's dead!