The occurrence of "puddling" behavior in Lepidoptera has been reviewed by M. J. Norris (1936) by J. A. Downes (1973) and by P. H. Adler (1982). Butterflies have been previously reported on mammalian dung, urine, perspiration, saliva, salt, blood, campfire ashes, aphid honeydew, tree sap and animal carrion. The rarity of female puddling in butterflies, particularly the tiger swallowtail (Papilio glaucus) has been recently addressed by two studies (Berger and Lederhouse 1985, Scriber 1987).
Scriber, J. Mark and Ayres, Matthew P.
"Observations on the Puddling Behavior of the Canadian Tiger Swallowtail Butterfly, Papilio Glaucus Canadensis in Northern Michigan,"
The Great Lakes Entomologist: Vol. 21
, Article 10.
Available at: http://scholar.valpo.edu/tgle/vol21/iss3/10