Animals
Raining cats and dogs
to rain heavily; pouring
Bug off
Leave someone alone; go away
All ears
eager to listen
Break a leg
Good luck
Ants in your pants
restless
Quiet as a mouse
silent or still
No spring chicken
Not young anymore
All thumbs
awkward and clumsy
Butterflies in your stomach
Nervous
At the drop of a hat
Right away
Cold turkey
the sudden stopping of a habit
Monkey business
fooling around
Apple of your eye
a person or thing that is greatly loved, treasured
Cat got your tongue?
Is there a reason you are not speaking?
Back to square one
return to the beginning
Fish out of water
a person who is out of his or her usual place
Till the cows come home
for a long, long time
Bite your tongue
struggle not to say something you want to say
Get under your skin
to bother or upset someone
Chill out
Relax
Crocodile tears
Fake tears
Snug as a bug in a rug
cozy, comfortable
Achilles' Heel
the one weakness, flaw or fault someone has
Elbow grease
Hard, energetic manual labor
Pull your leg
to tease or trick someone