The first few nights was not very noticeable and my workers went along their things to do with very little fuss.
The next few nights they notice something unusual. There were some kind of owl making a kind of cries on the BH roof between the zinc roof.
I still ignored their complains and put it aside.
During a short moment with the original owner of BH he swear to god that there is no way any owl will enter in between the roof and the cement slab.
So I took it for granted that there is no such thing as owl on the roof areas.
One day I brought a long aluminum pole for the hexagonal tweeter. During its installation it hit the zinc roof and whoosh an owl came out from nowhere and perched onto a rubber tree branch.
That night there were more owls around the BH.
We counted and there were almost 8 of them.
I knew that there must be a kind of nest(s) on the roof and decided to ask one of my worker to sneak in and take some photos.
The next morning we have the proof of four white eggs and two owls incubating them.
This must be on of the special reason why the BH was not doing well.
I told the owner that we need to remove the nests and the owl.
I came out with those clamp trap and my workers suggested to use those rat glues.
Just one night after the installation we caught the two tenants with five eggs.
The owner followed my suggestion to install special netting on the roof areas and we did help him out with the installation.
The two were given to the owner as a kind of prize and hopefully they know what to do with them.
The morale of this article is that if your BH host this unwanted tenant you need to find ways to remove them.
Your BH will remain empty or little tenants if they anchored their stay and add more to their clan.
Use everything that can help to prevent them from entering into your BH.
Set some traps like owl clamp, electrical shock wires, spikes nails on the window frames and perhaps some glue.
Try to identify where they will come and perch and set those trap there.
I am very glad that we managed to do something to remove the owls and hopefully the remaining six will not take over the nest.