Provide the idiom
Someone who is clever or skilful in a way that no one knew or expected.
A dark horse.
Someone barks is worse than his bite.
He may seem violent, furious but he is not.
This is a nice restaurant, so please try to mind your manners and not ...
make pigs of yourselves.
Feel that something is wrong.
Inform beforehand.
Let the cat out of the bag.
Someone who loves parties and socialising.
To take the travel bug.
A strong desire to travel.
Come on, Bill, go to sleep. You're just ... at this point, but you might have a breakthrough with the research if you take a break from it.
Go to the dogs.
Become run-down.
For the birds.
Someone who would love to be present to see an important private or secret event.
A fly on the wall.
Give someone free rein to do sth.
give someone complete freedom.
Everyone ... for the safari park as soon as they arrive on the estate.
Makes a beeline.
Fishy
Strange and suspicious.
From a reliable source.
Straight from the horse's mouth.
Someone who is not very friendly and does not show their feelings.
A little bird told me.
Someone told you a secret.
He looks big and dangerous, but he ... .
Wouldn't hurt a fly.
Take the bull by the horns.
take a decisive action in a difficult situation.
Play around.
Horse around.
Someone who acts as a subject in an experiment or trial of something.
A guinea pig.
To have butterfly in your stomach.
To feel nervous.
given me free rein
Horse of a different colour.
Can't talk?
Cat got your tongue?