Hello....is anyone there?

For the last few months, Lucy has made a habit of going up to the air vent, warbling for a good few minutes at the top of her lungs and then retreating. We've wondered if she's maybe heard a cat on the other side of it at some point and think's she can use it as her own little kitty communicator.

Some people use cups and string. Kitties apparantly use vents to speak to their outdoor kitty friends.