avoir le diable au corps

to be full of reckless, restless energy

Used for someone bursting with restless energy, often a bit wild or reckless with it, like a child who won't sit still or someone driving too fast.

Ce gamin a le diable au corps, impossible de le faire tenir tranquille cinq minutes.

That kid is bursting with wild energy, you can't get him to sit still for five minutes.

Goes back to 14th-century France and an old belief that the devil had superhuman powers. If it got into your body, people thought it would fill you with an unnatural burst of energy.