In message , Janet Bennett
writes
Meant to say which way should the opening face? North, South, East or
West.
Could I fix a box to the fence post????

Not south or west or the fledglings will cook - if the eggs haven't
already. Not sure a fence is the best place, as fence tops tend to be
cat promenades... on a wall or tree might be safer.

--
Klara, Gatwick basin