Lark is a term used to describe a person who likes to get up early in the morning and go to bed early in the evening.
Another name for a lark is a morning person or "early bird".
Larks tend to feel most energetic just after they get up in the morning.
Larks have a preference or habit for getting up early, which makes them well suited for working the day shift. If a lark has to work the graveyard shift, they may need to drink a lot of caffeine containing drinks in order to be able to do this. Larks who work the graveyard shift often have a problem with falling asleep if they don’t drink a lot of caffeine containing drinks.
The opposite of a lark is a night owl, someone who likes to stay up late.
In several countries, early birds (larks) are called "A-people" and night owls are called "B-people". Researchers traditionally use the terms morningness and eveningness.
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.