The series of three Zs making a Zzz represents sleeping, snoring, dreaming, or any other sleep-related state. It can also be used in certain situations to represent something that is boring.
If your neighbor is making an annoying sound next door or in the bed, use it. Alternatively, if you want to appear "asleep," send Zzz along with a?Sleeping Face or just a little?Sleepy Face, depending on your mood. To indicate that you plan to wake up early the next day, don't forget about the bed and?Full Moon and⏰Alarm Clock. So, no partying! No staying up all night!
U+1F4A4
? Sleeping symbol