When is a Raven Like a Writing Desk?

Riddle me this, riddle me that.
When is a raven like a writing desk?
A question that haunts us all.
What is the answer?
When is a raven like a writing desk?
At nighttime or day?
At three o'clock? Or noon?
When is a raven like a writing desk?
When the raven is asleep?
Or hunting for some food?
When is a raven like a writing desk?
Could a crow be like a writing desk?
Could a robin be one too?
When is a raven like a writing desk?
Why is it unlike a writing desk?
Are there only a similar few?
When is a raven like a writing desk?
Why can't it be a drawing desk?
Or a studying desk so true?
When is a raven like a writing desk?
Could it be just a table?
Or a notebook with drawings so blue?
When is a raven like a writing desk?
Is there even an aswer?
All that is up to you.