An information processing apparatus according to one aspect of the present invention is disclosed, which includes: an image acquiring unit acquiring moving images captured by a camera for watching a behavior of a watching target person on a bed or in the vicinity thereof； an image processing unit obtaining an optical flow within the moving images； and a behavior presuming unit, when detecting a moving-object based on the optical flow, assuming that the detected moving-object corresponds to the watching target person and presuming the behavior of the watching target person on the bed or in the vicinity thereof based on a position and a moving direction of the moving-object.
