Author Institution: Center for North American Bat Research & Conservation, Dept of Ecology & Organismal Biology, Indiana State University, Terre Haute, INAuthor Institution: Environmental Solutions & Innovations Inc., Cincinnati, OHSix species of bats (n = 272) were caught at Ravenna Training and Logistics Site during summer 2004: 122 big brown bats (Eptesicus fuscus), 100 little brown myotis (Myotis lucifugus), 26 red bats (Lasiurus borealis), 19 northern myotis (Myotis septentrionalis), three hoary bats (Lasiurus cinereus), and two eastern pipistrelles (Pipistrellus subflavus). Catch was 9.7 bats/net site (SD = 10.2) and 2.4 bats/net night (SD = 2.6). No bats were captured at two net sites and only one bat was caught at one site; the largest captures were 33, 36, and 37 individuals. Five of six species were caught at two sites, 2.7 (SD = 1.4) species were caught per net site, and MacArthur’s diversity index was 2.88. Evidence of reproduction was obtained for all species. Chi-square tests indicated no difference in catch of males and reproductive females in any species or all species combined. Evidence was found of two maternity colonies each of big brown bats and little brown myotis. Capture of big brown bats (X2 = 53.738; P <0.001), little brown myotis (X2 = 21.900; P <0.001), and all species combined (X2 = 49.066; P <0.001) was greatest 1 – 2 hours after sunset. Capture of red bats did not vary over the night (X2 = 7.083; P <0.461). Rate of capture was not consistent over the season for big brown bats (X2 = 28.603; P <0.001) or all species combined (X2 = 10.969; P = 0.004), but was similar for little brown myotis (X2 = 4.184; P = 0.123)