A Nifty Keep Out Sign

A nifty, short, and quite funny (if I do say so myself) "keep out" sign.

I made this up on a bleary Saturday morning because I was sick of my parents interrupting me while I tried to write. I'm not a poet as such, I can hardly ever rhyme anything, but I didn't think it was so bad for a just-woken-up piece.

The door is closed
As you can see,
There is no lock
There is no key,
But enter in
And there will be
S**t abound that
We don't want,
Do we?