This site sure is awesome....Don't know what I would do without it!
So Yen ended up moving the kittens to a new spot, which I would consider safer in terms of people, but I worry that it won't be warm enough. (she moved them to under my son's car bed but he doesn't sleep in it) So I do believe it was a combination of the smell plus she didn't feel like her kittens were safe in the place they were. Yuki is doing well tonight and showed great improvement from last night!