I've seen a fox running down my street a few times in the dark, but 2 nights ago , while I was in bed, I heard a terrible screeching noise. At first it sounded like a child screaming but it quickly came apparent it was a fox or foxes.
The noise was very dramatic and went on for a few minutes.

Is this a mating call , an argument, or just normal fox behaviour?

I don't know too much about them but I was curious about the screeching. It's always a lovely sight to see them slinking away in the moonlight.