Frog are said to have two lives because, THEY BEGIN THEIR LIVES IN WATER IN FORM OF EGGS AND THEN AS TADPOLE, BUT WHEN THEY ARE FULLY DEVELOPED THEY LIVE ON LAND. Thus, they live both on land and in water. Inside the water, the frog eggs hatch and become tadpoles. After some times, the tadpoles develop and become frogs, then they move out of the water and live on the land.