The article explores how natural and unnatural habitats affect the population of shrew-like insectivore Sminthopsis virginiae (Dasyuridae) in the Finniss River in Australia. The area consists of four habitat types which essentially composes of sedgeland areas and paperback forest areas with, and without mimosa. Findings show that S. virginiae is the most commonly captured species in the habitats. Results also reveal the difference in the abundance of the insectivore between pure mimosa stands and paperback forest with a mimosa mid-story. Results suggest that the decline in natural habitat contributes the rarity of some species like S. virginiae.