Typically air leakage is not effectively controlled with insulation. Several other important strategies are often used including sealing and pressure balancing of the air systems and air sealing of the thermal envelope of the building. Viewing air leakage can be tricky, because you are not seeing the air. You are seeing the effects of the air flow. Air moves in buildings due to pressure differences.
Warm air escapes out the top of the building.
It is replaced by cold air coming in the bottom. To see the effects of cold air infiltration look from inside on lower floors. Go outside and look at the upper portions to see the effects of warm air exfiltration. You can also simplify and enhance air leakage patterns by using a blower door fan or another means of creating an artificial pressure difference. It is not unusual to find air moving great distances through floor, ceiling, and wall cavities before you can actually feel it enter a room.