Is it a noisy bird who doesn’t sleep?

We have a sound every night since May. Starts about 11pm until morning and is so loud it wakes us. It is a drilling/vibrating noise above our upstairs 

 We do not hear it during daytime.

Thought it was a woodpecker, but now thinking maybe a crow. It’s intermittent. No sound can be heard in the loft and at times it  can be heard in the distance so obviously flies around.  No neighbours hear it.

What bird would do this and will it ever go away?

Driving us insane. Any thoughts please