Bee-Gap describes the ecology, life-history, and distribution of 3,925 bee species in the United States that have geographical data and verified taxonomy. The database was constructed by compiling information from a broad range of internet sources and peer-reviewed journal articles. The 10 traits included in the database are: native status (native versus exotic/introduced), state and territory presence/absence, adult habitat, nesting strategy, voltinism, sociality, host bee species (for parasitic bees only), foraging strategy (generalist vs specialist), known host plants, and tongue length.