You might not be as observant as I am.
I tend to spend more time in studying those birds behavior during their approaches to BH that I took charged to revamp.
I is clear that if the orientation of the entrance hole is not properly done there will be a lot of lost opportunities.
A good example is when the BH owner installed his hexagonal tweeter at a wrong location or perhaps the hexagonal tweeter is too high above the main entrance hole.
When those wild birds come to your rooftop, and cannot locate the entrance hole they will move away and you will miss an opportunity to lure them into your BH.
Other than the precise location of the hexagonal tweeter I also have something to talk about having an open roof entrance on the roof of your monkey house.
The Teluk Kalong BH that I recently visited seems to show some awkward bird behaviors.
This stand alone BH is with a monkey house with an opened roof top.
The moment those wild birds came to the hexagonal tweeters they will become frenzy and stated to search for any hole to enter the monkey house roving area.
Their preferred entry hole are on the walls and not the rooftop.
I can see that they will be circling the entire four external walls of the monkey house searching for hole(s) to enter.
Sometime due to the wind direction there will be a preferred wall where most of them flying like queuing to buy a cinema ticket.
Just imagine if that particular particular location is with a hole and installed with external sound tweeters?
You will have a higher chances to draw a much higher percentage of your daily visitors into your BH.
My conclusions from this recent observation made are:
a) Try to avoid erecting a monkey house with open roof entrance system.
b) A Monkey house should be tailored to side entrance and not top entrance.
c) If you wish to have a top entry system you need to take away or reduce the four walls height to not more that 2 feet high and with a slanting configuration.
d) Young birds prefer the side entrance hole more as compared to top entrance hole.
e) Matured birds tends to prefer top entrance system.
You might want to consider dual entries if you wish to get all the benefits but for a new BH focus on monkey house with side entrance.