Shell midden sites are situated at Kusu Midden and Valu Beach Midden. One form of midden analysis examined the size of fecal pellets in pack rat middens. A shell midden or shell mound is an archaeological feature consisting mainly of mollusk shells. This archaeological exhibition is located inside a prehistoric shell midden. Surveying of the midden suggested extensive prehistoric construction activity. A pack rat midden is a debris pile constructed by a woodrat. The garderobe was replaced by the privy midden and pail closet in early industrial Europe. A ring midden in the camp provided a radiocarbon date of 1300 AD. Accurate dates were obtained from moa egg fragments found in grave and midden sites. The midden at Daisy Cave is the oldest coastal shell midden in North America. Isle of the Dead retains a large midden. Additionally, a burned dwarf mammoth in a shell midden was dated to 12,500 years BP. Gradually the buildings fell into ruin, becoming a midden (waste dump). Several features of the village, including houses and midden pits, were built over. The Whaleback Shell Midden is now a state historic site.