Exploratory data analysis consists of multiple iterated steps: a data mining method is run on the data, the results are interpreted, new insights are formed, and the resulting knowledge is utilized when executing the method in a next round, and so on until satisfactory results are obtained. We focus on redescription mining, a powerful data analysis method that aims at finding alternative descriptions of the same entities, for example, ways to characterize geographical regions in terms of both the fauna that inhabits them and their bioclimatic conditions, so-called bioclimatic niches. We present Siren, a tool for interactive redescription mining. It is designed to facilitate the exploratory analysis of data by providing a seamless environment for mining, visualizing and editing redescriptions in an interactive fashion, supporting the analysis process in all its stages. We demonstrate its use for exploratory data mining. Simultaneously, Siren exemplifies the power of the various visualizations and means of interaction integrated into it; Techniques that reach beyond the task of redescription mining considered here, to other analysis methods.