From my experience, I do believe that aroma does help to extract birds. But the problem is when you apply aroma, it will not last for long. The most 1 or 2 weeks? If we can make the aroma smell
consistently contain in the
BH and make the birds think that this is the "OLD"
BH, do you think more birds will come in? If yes then the next question is how can we do that?
So far, I can only think of 2 methods but I have not tried it out yet. 1st method is try to use the concept of "Glucose Drip method". If we can control the aroma slowly dispense into the humidifier, then we can make sure the aroma will consistently present in the
BH.
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2
nd method is use the used Car perfume. Pour the aroma in the car perfume and use computer fan to blow the aroma to the ground. The air flow from this mini fan is weaker than the humidifier and should not disturb birds. The problem is, you have to make sure the smell of car perfume is totally clear before you use.
Personally, I prefer to use the car perfume as is easy to setup. If you have any good idea, do let us know.