Dynamic queries are user-controlled animated displays of visual or textual data. On an application developed for the National Center for Health Statistics and running on their ordinary staff equipment, a thematic map of the United States is animated by moving a time slider to illustrate trends of mortality rates. Other sliders filter parts of the maps interactively according to parameters such as demographics. During the filtering possible correlations can be observed as they create color patterns in he "dissapearance" of the states. This application has been received with enthusiasm by the user community and will be distributed with selected new datasets.