What are some annoying habits you do that you notice but don't realize, yet others do?

Hm most people have habits, big and little. Me for example when ever I get food I start humming a song that’s in my head (songs are always some where in me haha), or I grind my teeth when I sleep (so says my sister) or I listen to much. But yes those are some of my annoying things that I notice but don’t realize till someone tells me. I know my sisters notices it, but what are some things you do? Is it bad that I do these things anyways?