Weibchenkolonien im Sommerquartier; Geburtsvorgänge mit aktiver Mithilfe des Jungen bei der Geburt, Spannen der Nabelschnur und Abnabelung; Nahrungsaufnahme vom Boden, Freßverhalten; Schwimmen und Aufflug vom Wasser; Paarbildung, Begattung und Überwinterung in gemischten Kolonien.

The film shows the most important biological characteristics of Myotis myotis in the course of one year which, at the same time, reflect those its life. A cave in the "Fraenkische Schweiz" is shown as its winter quarters, the summer quarters (i. e. the lying-in-room) being on the loft of St. Martin's Church at Bamberg. Interesting ways of acting are rendered by the proceedings of birth; it is the active assistance of a young one during parturition, the tightening of the navelstring and the act of detaching it that is unparalleled among mammals. Food intake from the soil, way of eating, swimming as well as the surprising flushing from water show some ways of living of Myotis myotis. The cycle of the year is concluded by the return into winter quarters.