The 'nests' aren't built from twigs at all — swiftlets glue them together almost entirely from their own hardened saliva, harvested by hand from sea caves on the Myeik Archipelago's islands.
Swiftlet nests gathered from limestone caves on offshore islands are simmered down into a clear, gelatinous broth, traditionally sweetened with rock sugar rather than served savory. It's sold as a prized specialty in Myeik and Dawei rather than an everyday street snack.