On four different days over the past two weeks there has been this drilling-type noise coming from above my bedroom where the upstairs furnace is located.  It only happens sporadically and, usually, in the mornings but not enough to really figure out what was going on.  After having some conversations with the heating & cooling people who put the thing in originally, we were down to either a vibration with one of the pipes or an issue with the furnace (they were tentatively scheduled to come out this Friday to check things out).
 
Well, this evening I heard the racket again and decided to go out into the backyard on a hunch.  There, on top of the highest roof vent cap that goes directly down to where the furnace is (and my bedroom) was the answer.  Here's an example of the problem except that the acoustics with my roof vent and pipe are FAR better than a street light!
 

 
Now, I'm a nature lover but, if this keeps up, there may be one less bird around the neighborhood! 
 
 

 
Just saying...

Oh I've got a yard full of the neighbor's kitties, but I like MOST of my birds (usually the little ones) so they know to stay where the rodents are and leave my friends alone.  But I'll definitely consider throwing a cat up on the roof if that woodpecker keeps drilling the vent!

https://www.youtube.com/watch?v=ZCOG5RnpzUo
 
 
We have this one kind of bird around here - they have such an incredible "vocabulary", they make the craziest sounds. Sometimes you'd think they're impersonating R2-D2, other times you really get the impression that they're laughing their bird's arse off.
 
They seem to like the huge pine trees - of which we don't have any but almost all our neighbours seem to have one. They can really ruin a quiet moment - and since I like to read outside in the backyard, they do annoy the heck out of me.
 
I never really liked birds, and my aversion only got worst after I met Joe Crapper in NY.
 
 

Actually the northern flicker sounds like a small jackhammer, not a drill per se. 

slartabartfast
Actually the northern flicker sounds like a small jackhammer, not a drill per se. 

You are correct.  I meant to say jackhammer actually.
 
@Rain - I like birds, but I consider pigeons as dirty rats with wings (actually, that's too demeaning to rats).

This video's closer to what I hear amplified in my bedroom.
 

That's some serious headbanging!

Must be a drummer.

 
I think the question needs to be asked.
 
Do you think that woodpecker would like to be your friend?
 
Well....
 
.... woody?
 
 
 
 
 
 
 
 
 
 
 
 
 
Yuk yuk - you see what I did there.... ya etc?