Elinor Wonders Why Season 9 Episode 1 The Little Drummer/Rest is Best

Ari is showing off his new drum moves to Elinor and Olive when Ari's mother asks him to be quieter so Ari's sister can take a nap. Then, after Olive stays up most of the night reading a fun book, she decides she's going to stay up late every night until she finishes. That makes the kids wonder, why do they need to sleep anyway?