Detect Familiar

For the duration, you sense the presence of any creature that's currently serving as a familiar within 30ft of you. If you sense a familiar in this way, you can use your action to see a faint aura around the creature. In addition, you're able to sense if its master within 1 mile of your location and know their general location.

The spell can penetrate most barriers, but is blocked by 1ft of stone, 1 inch of a transition metal, a thin sheet of lead, or 3ft of wood or dirt.