The tawny crazy ant, Nylanderia fulva (Mayr) (Hymenoptera: Formicidae), is an invasive ant from South America with overwhelming populations that invade structures and overrun landscapes. To contribute to the development of biologically based control strategies for this ant, the seasonal prevalence of queens, males, and brood within colonies of N. fulva was determined from monthly collections of colonies located in north central Florida. The average number of queens per colony was significantly greater in the winter and spring than summer and fall. The fall and winter male counts were significantly higher than the other 2 seasons. Brood was most prevalent in the spring and fall and significantly greater than the brood collected in winter. Comparisons of queen, male, and brood to worker ratios generally had similar results to the average counts of queens and males and brood volume per season. The seasonal fluctuations in levels of queens, males, and brood reflect the winter coalescing of colonies into larger, permanent nest sites, and the summer dispersal of smaller colonies into transient nest sites located throughout landscapes.