Migrating bats are among the most poorly understood of migratory taxa, with relatively little information available on their behavior and ecology during migration compared to other taxa. This arises because of the “small animal problem,” namely the limitations of current technology to track individual animals that weigh <190 g. In this paper (which is not a comprehensive review of bat migration) we assess the limits of current techniques available to study the migratory behavior of individual bats and what is needed to take the study of the behavior and ecology of migrating bats forward.