A carrion study of the baby pig, Sus scrofa Linnaeus, was conducted during the summers of 1962 and 1963 in a mixed mesophytic hardwood—pine community at Clemson, South Carolina. Six stages of decomposition were delimited for carrion exposed to arthropods: fresh, bloated, active decay, advanced decay, dry, and remains. Five stages were recognized for carrion protected from arthropods: fresh, bloating and decomposition, flaccidity and dehydration, mummy, and desiccation and disintegration. Carrion free of insects decomposed and dried very slowly, retaining its form for many months, while 90% of the carrion open to insects was removed in 6 days. Carrion temperature during the bloated through advanced decay stages differed widely from that of air or soil. A definite ecological succession occurred among the fauna of carrion. Each stage of decay was characterized by a particular group of arthropods, each of which occupied a particular niche. Their activities were influenced by physical properties of carrion, rapidity of putrefaction, time of day, and weather. A total and 522 species representing 3 phyla, 9 classes, 31 orders, 151 families, and 359 genera were collected from decomposing pigs. Four orders of arthropods (Coleoptera, Diptera, Hymenoptera, and Araneida) accounted for 78% of the carrion fauna. Two coleopterous families, Histeridae and Staphylinidae and three dipterous families, Sarcophagidae, Calliphoridae, and Muscidae, represented 26% of the fauna.