Lark (person)

A lark, early bird, or morning person is a person who usually gets up early in the morning and goes to bed early in the evening.

The lark (bird) is primarily diurnal, which explains the choice of the word "lark" for people who may sleep from around 10 p.m. to 6 a.m. Larks tend to feel most energetic just after they get up in the morning. They are thus well-suited for working the day shift.

The opposite of a lark is a night owl, someone who usually stays up late and may feel most awake in the evening.

In the Scandinavian countries, such people are called "A-people" and night owls are called "B-people". Researchers traditionally use the terms morningness and eveningness.

Prevalence
Discussions and studies about the prevalence of morning, evening and indifferent or intermediate chronotypes use different criteria and come to different results. Some ask what time people do go to sleep and wake up—others ask what time people would prefer to. A survey of over 400 adults showed approximately 15% morning people, 25% evening people, and 60% intermediates.