In Pattani, Thailand, the real estate market is being dominated by investors looking to attract swifts. These tiny birds are being welcomed into unused upper stories, empty basements, and roofs. Their abandoned nests are harvested by building owners for a tidy profit at $1,000 a pound. Soaked, cleaned, and cooked, the nests are the basis for the famous delicacy, bird’s nest soup. Building owners use various tactics, such as recorded birdsongs, to try to entice swifts to nest within their walls.