The objective of this study was to obtain information on the food of the free-tailed bats under the Congress Avenue Bridge in Austin, Texas, because these bats are so well known. We collected guano there on three occasions. The dominant foods in October 1991 were moths, beetles (particularly leaf and ground beetles), and true bugs (particularly leafhoppers and chinch bugs). In September 2013, the major foods were moths, flies (particularly crane flies), true bugs (particularly leafhoppers), and beetles (particularly leaf beetles). In 1991 few bats remained under this bridge in winter, but by 2012–2013, many of the bats remained all winter. In winter, flies and moths were the dominant foods.