Edible bird's nests are bird nests created by edible-nest swiftlets, indian swiftlets, and other swiftlets using solidified saliva, which are harvested for human consumption. they are particularly prized in chinese culture due to their rarity, high protein content and rich flavor. edible bird's nests are among the most expensive animal products consumed by humans, with nests being sold at prices up to about $3,000 per pound ($6,600/kg), depending on grading. the type or grading of a bird's nest depends on the type of bird as well as the shape and color of the bird's nest. it is usually white in color, but there also exists a red version that is sometimes called "blood" nest. according to ...

Source: Wikipedia