A movable object for responding to an object includes a first passive infrared sensor having a first detection range and a first field of view, and one or more second passive infrared sensors each having a second detection range and a second field of view. The second detection range is longer than the first detection range and the second field of view is smaller than the first field of view. The movable object further includes one or more processors configured to recognize the object based on one or more heat signals received from at least one of the first passive infrared sensor or the one or more second passive infrared sensors, and perform a flight response measure to control the movable object based on the recognized object.