THE CHALLENGE WE'RE GONNA BUILD RIGHT NOW IS THE HIDDEN ALARM.

SO WE'RE GONNA MAKE A CIRCUIT, AND THE CIRCUIT IS GONNA HAVE A BATTERY AND A BUZZER IN IT SO THAT WHEN WE CLOSE THE CIRCUIT, THE BUZZER'S GONNA GO OFF.

AND WE'RE GONNA MAKE A SIMPLE CIRCUIT TO SHOW HOW THAT WORKS, AND THEN THINK ABOUT WHAT KIND OF CRAZY THINGS WE CAN DO WITH A BUZZER AND AN ALARM.

WE HAVE BATTERIES, A BATTERY HOLDER, AND THEN WE HAVE DIFFERENT KINDS OF BUZZERS, ALUMINUM FOIL, CARDBOARD TO BUILD A CIRCUIT ON.

WIRE STRIPPERS.

WIRE STRIPPERS.

RIGHT.

AND IF WE REALLY NEED IT, YOU'VE GOT WIRE AND TAPE, OF COURSE.

OK. LET'S DO IT.

I'M GONNA MAKE ONE THAT GOES OFF WHEN I SIT DOWN.

IT'S GONNA BE A CHAIR-- A CHAIR ALARM.

I THINK I MIGHT DO SOMETHING MORE LIKE THEFT PROTECTION.

I'M GONNA START AND MAKE A REALLY SIMPLE ONE JUST TO SHOW HOW THE CIRCUIT WORKS.

SO I'M JUST GONNA TWIST IT TOGETHER LIKE THAT.

AND THEN I'M GONNA PUT SOME TAPE ON IT JUST TO HOLD IT TOGETHER.

THAT'S ONE.

ALL RIGHT, SO MY WIRES DON'T ACTUALLY HAVE TO TOUCH EACH OTHER.

WHAT I'M GONNA DO IS TAKE THIS WIRE AND TAPE IT TO THIS PIECE OF ALUMINUM.

AND WHAT SHOULD HAPPEN NOW IS WHEN I TOUCH THIS WIRE TO THE ALUMINUM... [ALARM BUZZES] IT CONNECTS THE CIRCUIT.

SEE THAT?

JUDY: I'M GONNA MAKE MINE SMALL ENOUGH, KIND OF USING THE FRONT AND BACK SIDE AS THE CIRCUIT BOARD.

'CAUSE WHAT I WANT TO DO IS ACTUALLY STICK IT IN THIS CAN.

WE'VE GOT THE ENTIRE CIRCUIT IN THERE.

I'VE ATTACHED IT TO THE CAN.

THE WHOLE CAN HAS BASICALLY BECOME CONDUCTIVE BECAUSE IT'S MADE OF ALUMINUM.

WHEN ADAM COMES TO GRAB THE CAN, IT'LL MAKE CONTACT... [ALARM BUZZES] AND BUZZ.

I'M GONNA HIDE IT WITH THIS PIECE OF FOIL SO HE CAN'T TELL IT'S THERE.

ADAM: OK, I'M GONNA TAPE THIS TO THE BOTTOM, GONNA TAPE MY BATTERY ON HERE.

[ALARM BUZZING] THERE IT GOES.

IT'S WORKING.

NOW I'M GONNA MAKE A LITTLE HINGE SO THAT THIS THING IS GONNA WANT TO STAY SORT OF SPRUNG UP, BUT WHEN I SIT DOWN... [ALARM BUZZES] TAPE THAT DOWN.

[ALARM BUZZES] JUDY, YOU LOOK TIRED.

YOU'VE BEEN MAKING CIRCUITS ALL DAY LONG.

YOU WANT TO HAVE A SEAT?

I AM.

YEAH, OK. TAKE A REST.

THANKS.

[ALARM BUZZES] OH!

OHH!

THAT'S PRETTY COOL.

I'M TIRED.

I'M THIRSTY.

I WANT A DRINK.

THERE'S A SODA THERE.

[ALARM BUZZES] OH!

HA HA HA!

NOT BAD.

I LIKE IT.

NICE JOB.

[SLAP HANDS] I JUST TOOK A PICTURE OF MY ALARM, AND I'M GONNA UPLOAD IT TO THE WEBSITE.