A detailed description of a method for collecting meal and drinking bout patterns for the rat over 24-h preference tests is presented. Both the hardware and software are described for data collection with a 6-s resolution. As an example of the value of knowing the details of ingestive patterns, data are presented describing the meal and drinking bout patterns during daylong preference tests between sucrose or saccharin vs. water. During these two-day tests at each of a wide range of concentrations, the intake of powdered Purina Chow, sucrose and saccharin were observed and quantified into meals or bouts. The analysis allowed for a comparison of sucrose and saccharin ingestion in terms of number of bouts, duration of bouts, rate of licking during bouts, the juxtaposition of eating and drinking and the day/night patterns of intake. Comparisons of drinking during bouts were made with electrophysiological and short-term taste test data. The usefulness of microstructure analysis is discussed.