In order to observe and record the behaviour of Triatoma infestans in relation to movement, position and physiological state, like the ethologists commend, a mud-walled thatch roofed house within an external transparent acrilic protection was built. To record the bug activity a time-lapse cinematographic tecnique using a super-8 mm movie camera synchronized to and eletronic flash and programmed for simultaneous shots of one photograph every 30 seconds was employed. The analysis of the data was done with super-8 mm film projector and a movieola editor which allowed the observation of each photograph. After six days of continous observation by this method the following statements could be made: a) In the absence of the alimentary stimulus the locomotory activity in T. investans does not occur, being day or night, even if the insect is deprived of its blood-meal, b) In presence of an alimentary stimulus the locomotory activity takes place during 24 hours a day, althought in greater significant proportion in the darkness.