Hold your horses
Burn the midnight oil
Ants in one’s pants
Can’t stay calm (relax) because you’re nervous
Work until late at night
Very expensive
It’s not hard.
Don’t start problems or cause trouble
Cost an arm and a leg
Let sleeping dogs lie
It’s not rocket science
Wait and be patient
Once in a blue moon
Happens very rarely; uncommon
Tell a secret
Best thing since sliced bread
Let the cat out of the bag
Good idea or invention
