Counting money that fly in the sky

Nephew Eric was looking up in the sky and counting 500, 1000, 1500..... Curious, I asked where were those figures. There weren't any numbers in the sky as far as I could see.

'Oh, you see those swift-lets flying around?' I looked up where his finger indicated. 'Each of those birds can fetch in RM500 worth of nests every harvest,' he declared.

'Hmm...' I said. 'And how do you aim to get those nests?' I asked, triggering him to tell me more.

He went on to describe how to set up swiftlet breeding houses, the materials required, temperature and humidity control devices, and sound systems and speakers and what-nots to attract the birds to come in and build nests, short of sending them invitation cards. He appeared to have acquired quite an expertise in the field. He'd personally built about half a dozen bird-homes by then, and getting requests to build more, though he admitted, it was by trial and error learning experience.

Those of you who have watched 'The Little Nyonya' TV series should have an inkling how good swiftlet nests are for their medicinal value. They were shown to have nursed the heroine and brought her back from the brink of death after she was left for dead in spite of a dramatic rescue from being drowned in a well by the hero.

As the heroine herself eventually testified, the real hero were the swiftlets which built their nests in that particular abandonned building into which she was thrown.

Back to bird nests, I asked him about those we see sitting on electrical wires running through town. He said those are not the swiftlets that build the kind of expensive medicinal nests we see in medical shops. Those weave nests out of grass. They're of a diferent species.
That ends lesson one on bird-nests of which I heard so much but knew very little about, except that they're too damned expensive for our taste.
Next time you're out in town and hear birds chirping and squeaking right into the middle of the night, don't be mistaken that you're hearing things. It's probably some bird-nest breeder didn't set the correct timing to his bird-calls. They should be shut down after sundown when all the swiftlets are already home and busy building nests with their vomit...
To think they were originally reserved for the emperors. Now everybody can try.