This small, 30-cm-long (1-ft-long) creature probably lived in large freshwater lakes, like present day beavers. A semiaquatic lifestyle is indicated by the presence of combing-claws, which living beavers use to waterproof their fur. Most likely, it was incapable of bringing down trees like its modern relatives. Steneofiber was more terrestrial than modern beavers, living in burrows. The finding of a possible family group of Steneofiber skeletons in France has been used to infer that the genus employed a K-selected reproductive strategy like modern beavers, in which extensive parental care is given to a small number of offspring. Steneofiber is among earliest known members of the subfamily Castorinae, which includes beavers more closely related to the two living species than to the recently extinct giant beaver. It is probably descended from the earliest castorine, Propalaeocastor.