A lark, early bird, morning person or, in Scandinavian countries, an A-person, is a person who usually gets up early in the morning and goes to bed early in the evening. The lark (bird) starts its day very early, which explains the choice of the word lark for people who may sleep from around 10 p.m. to 6 a.m. or earlier. Human “larks” tend to feel most energetic just after they get up in the morning. They are thus well-suited for working the day shift.