Although agricultural needs are pressing and crop sales are vital for the local economies in southern Ohio, the resulting clearing of land has removed much of the state’s forests and natural prairies. A variety of species depend upon these habitats that have been reduced resulting in a potentially narrower ecological niche. In this study, we seek to determine the species richness and diversity of small mammals in three habitats (old field, forest, and lawn) and to evaluate factors affecting their activity. Our experimental results supported our hypothesis that the lawn site would have lower diversity than the other two sites. We captured and identified to species a total of 72 individuals in 512 trap nights (14% capture rate) with 30, 33, and 9 in the old field, forest, and lawn sites, respectively. The Shannon Index of diversity (H’) for the lawn was lowest (H’ = 0.49) with just two species observed. In contrast, we documented the greatest diversity (six species, H' = 2.26) in the old field. Intermediate to these two sites we identified five species in the forest (H’ = 1.46). There was also a low community similarity between the plots, suggesting that increased landscape diversity (patches of varying habitat) may also boost landscape biodiversity. We noted that there was no correlation between captures and weather conditions suggesting activity was not impacted by weather in this study. Furthermore, we observed that in the forest, species were captured on the first trap day; however, in the old field and lawn, species were not captured until days 6 and 12 of our 19-day study.