Thank you for those who left a comment and advice about the bug problem. Of course I dreamed about the critters all night. The art with the bugs spent the night on the balcony and in the morning I examinated the damage. I decided to throw away the most damaged stuff, because I could see myself debugging the woolen art dolls.
I was very sorry to throw them away, but maybe all things just have to live this cycle of coming and going. Transformation. My heart bled as it have been 3 art dolls and one collage from Johanna. The collage was with felt and as you can see on the photo the bugs managed to eat holes into the felt.
As for the altered book and a felted cat by me, there has been no visible damage and other bugs than I removed, so I put them in the freezer wrapped in plastic bags. Within the coming week I will put all the art I have in my box into separate plastic bags to avoid having this again. And I truly hope the bugs are not somewhere else, too.
Maybe it also has been a sign of the universe to declutter again (or the more?) So my advise: Always check your natural materials and art! The bug damaged happened in front of my nose on the shelf and I didn't recognize it. And I can't even say that I have a messy and dirty home. Bahhhh.