Genesis 8:7

He sent forth a raven. Forty days after the appearance of the mountaintops, Noah became anxious to know the extent to which the waters had dried up, and whether it was safe for him to leave the ark. As the waters had abated, the ark had already found safety from the tempests in a sheltered spot high in the mountains. From such a position it was difficult to ascertain the extent to which the waters had receded in the lower valleys. A raven was therefore dispatched, that Noah might observe from its behavior something of the condition of the earth. Not able to find a resting place, the raven flew about over the surface of the waters, returning from time to time to the ark (PP 105).