Otter females are called bitches or sows, and their offspring are called pups. The collective nouns for otters are bevy, family, lodge, romp (being descriptive of their often playful nature) or, when in water, raft. The feces of otters are typically identified by their distinctive aroma, the smell of which has been described as ranging from freshly mown hay to putrefied fish; these are known as spraints. The gestation period in otters is about 60 to 86 days. The newborn pup is cared for by the bitch, dog and older offspring. Bitch otters reach sexual maturity at approximately two years of
Mammal Species of the World Mammal Species of the World Mammal Species of the World: A Taxonomic and Geographic Reference is a standard reference work in mammalogy giving descriptions and bibliographic data for the known species of mammals. It is now in its third edition, published in late 2005, which was edited by Don E. Wilson and DeeAnn M. Reeder. An online version is hosted by Bucknell University, from which the names of the species can be downloaded as a custom dictionary. A partial online version is available at Google Books (see "External links" below). The Checklist Committee is charged with compiling and updating MSW.