I agree, animals usually get agitated over something. With the dogs it's usually something like coyotes or other dogs outside... something tangible. With cats it's an interference in the force or ripples in the astral plane... something that mere human senses can't detect.

Here are the cats. Houston, We Have a Problem is on top and Riley is in the tube. (Sorry it's sideways. I tried to fix it, but it still copied sideways.)