Frio Bat Cave, just south of Concan, Texas, is summer home for 10-12 million Mexican free-tailed Bats. The bats begin to come out of the cave entrance at dusk and may fly hundreds of miles a night in search of insects. Raptors often wait for the bats to appear to grab an easy meal. The night we visited the cave was overcast and misty; there were very few hawks.