up with the lark up very early in the morning.

☞ References to the early-morning singing of the lark date back to the 16th century: the first recorded instance is found in John Lyly's Euphues. Early risers are often referred to as larks, while their late-to-bed counterparts may be described as owls. The phrase also employs a play on the word up, since the lark sings on the wing while flying high above its nest.