ants in one’s pants

People who have ants in their pants are very restless or excited about something.
“I wish he’d relax. He’s got ants in his pants about something today.”

with bells on

If you go somewhere with bells on, you are delighted and eager to go there.
“Of course I’ll be there – with bells on!”

bounce off the walls

Someone who is very excited about something, or full of nervous energy, is said to be bouncing off the walls.
“Danny can’t wait to start his new job. He’s bouncing off the walls.

bright-eyed and bushy-tailed

A person who is bright-eyed and bushy-tailed is very enthusiastic and full of energy.
“Gary was fantastic. He arrived bright-eyed and bushy-tailed at 7am and worked with us all day”

cause a stir

If something causes a stir, it creates an atmosphere of excitement or great interest.
“The arrival of the actress caused quite a stir in the village.”

champ at the bit

Someone who is champing at the bit is ready and eager to start an activity, and is showing impatience at being delayed.
“The press conference was delayed for such a long time that the journalists were champing at the bit.”

dial it back

If you dial it back, you reduce the intensity of something, or tone it down.
“When Lucas started getting all excited, his mother said : Hey Lucas, dial it back a bit!”

do nothing by halves

When a person does everything they are engaged in completely and thoroughly, they are said to do nothing by halves.
“When she cooks, it’s always a four-course meal – she does nothing by halves!”

eager beaver

The term eager beaver refers to a person who is hardworking and enthusiastic, sometimes considered overzealous.
“The new accountant works all the time – first to arrive and last to leave. He’s a real eager beaver!”

eat, sleep and breathe something

If you eat, sleep and breathe something, you are so enthusiastic and passionate about it that you think about it constantly.
“He’s an enthusiastic golfer; he eats, sleeps and breathes golf!”

(on the) edge of one’s seat

Someone who is on the edge of their seat is very interested in something and finds it both extremely exciting and nerve-wracking.
“Look at Bob! He’s on the edge of his seat watching that rugby match!”

fever pitch

If a situation or feeling reaches fever pitch, it becomes very intense and exciting.
“Reaction to the affair has reached fever pitch all over the country.”

fling yourself into something

If you fling yourself into an activity, you do it with a lot of energy and enthusiasm.
“Ever since she flung herself into the anti-pollution campaign, she rarely has a free moment!”

go the extra mile

If you go the extra mile, you do more than what is expected of you.
“You can count on Tom; he’s always willing to go the extra mile.”

hold your horses

If you tell someone to hold their horses, you think they are doing something too fast and should slow down and not rush into further action.
Hold your horses! We need to get the customer’s approval first!”

lick/smack your lips

A person who is licking (or smacking) their lips is showing that they are excited about something and are eager for it to happen.
“He was licking his lips at the idea of all the money he was going to make.”

put your heart (and soul) into something

If you put your heart (and soul) into something, you are very enthusiastic and invest a lot of energy and hard work in it.
“Paul was determined to make a success of the project. He put his heart and soul into it.”

raring to go

If someone is raring to go, they are very eager and enthusiastic about the idea of doing something.
“The kids can’t wait to go camping. They’re raring to go!”

run out of steam

If you say that a person, a process or an organised event is running out of steam, you mean that there is a loss of impetus, energy or enthusiasm.
“The anti-immigrant movement seems to be running out of steam.”