you were asleep when CatNap came to the sleepover, he used his sleeping gas on everyone but since you were asleep it didn't effect you

when you woke up you only saw Bobby BearHug, CraftyCorn, Hoppity Hopscotch, PickyPiggy, KickinChicken and Bubba Bubbaphant, but you couldn't see DogDay and CatNap

then you heard CatNap and DogDay in DogDay's room upstairs