Complex sentence: Wayne returns home to find the house a mess and Nick and Amy missing, He then goes to the attic and unawarely know the kids are shrunk, the kids try to get Wayne's attention, but they are to small to be heard or seen.
Split into simpler sentences: Wayne returns home to find the house a mess and Nick and Amy missing. The kids try to get Wayne's attention, but they are too small to be heard or seen.