I see that you also have a cardboard chewer! Those unmistakable bits of munched cardboard that are discarded on the floor for a human to clear up appear every time I have a box in the house.

Amazing news! They are adorable! Be prepared for bounce, eat, bounce, sleep on rotation & pitiful meows if you dare to leave them alone in a room. Also block even the tiniest gaps in preparation. Kittens are a liquid. I once had one find a tiny gap in the kitchen boards and end up under the cooker.