Jennifer wrote:
....
...the [bat] house must be visible from the south
at all times. If tree branches or other structures obstruct the house,
bats are unlikely to ever find it.
....

I have no clue where this piece of the recipe came from but I can attest
that bats found the eave vent on my house which definitely didn't not
face nor was it even visible from the south...of course, the house was
in "the South" if that counts...

Methinks this is legend, not fact.