Caterpillar Locusts.
It's just a lone makeshift shack that's allowed to stand on a long stretch of mangroves. It houses a tailoring-shop run by a pious old man but he's a pioneer. Soon others will set up shop and homes around him and before you know it the mangrove forest will be gone. I know, because all the places I have lived in Mumbai have been built on what was once mangrove swamps.