A technique involving time-lapse cinematography was developed for studying the behavioral repertoire of planorbids in laboratory conditions. Observations were carried out within a chamber with controlled light and temperature; recording was done by single frame shooting at 10 second intervals, with synchronized strobed flash. This technique has allowed accurate measurements of different aspects of the activity of Biomphalaria glabrata (Say, 1818), and can be useful in analysing the level of response of planorbids to molluscicides, in experimental tests, as well as their protective behavior under general adverse conditions.