Biologists have long argued that individuals avoid extreme inbreeding in order to reduce the probability of producing genetically inferior offspring through inbreeding depression. Support for this argument is scarce, since only for humans and certain plants is there unequivocal evidence from the same species for both the avoidance of extreme inbreeding and inbreeding depression. Black-tailed prairie dogs living under natural conditions in South Dakota avoid extreme inbreeding by four different mechanisms, but preliminary evidence from 19 inbred litters indicates that there is no inbreeding depression. Research to further investigate the apparent lack of inbreeding depression among wild prairie dogs is proposed. Infanticide as well as communal nursing has been observed nearly simultaneously in this species. Similar communal nursing has been observed in only a handful of mammalian species, and never before in a rodent living under natural conditions. Research to further investigate the shift from attempted infanticide to communal nursing in prairie dogs is proposed.