Purple, reading your post reminds me of something that happened years ago. I was new to houseplants and had recently brought a pot of Swedish ivy. For a couple of nights DH and I kept hearing this scratching/munching noise in the bedroom. We turned the lights on and looked around, but couldn't locate the source. I looked at the plant, but didn't see anything unusual. Yet, it sounded so loud and so close.

We were afraid that we had rodents in the bedroom walls, as the noise seemed to resonate. Well, a day or 2 later, I noticed that my swedish ivy wasn't as full. In fact, pieces had begun falling on the floor. I didn't have time to investigate, as I was running late for work and left. When I got back home, the plant was nearly totally defoiliated.

Then I heard the munching noise and saw a piece of the plant drop to the floor. I took a closer look at the plant and found a couple of well hidden, fat tomato hornworms having a feast and killing my plant.

DH got rid of the culprits. The plant looked terrible for quite a while, but eventually recovered. I'm glad that you're not seeing that kind of damage.