Prabhakaran 7th grade student from Isai-Ambalam school.He comes to Stem land on every Saturday and works on his own doing soldering and tinkering some electronics kit. He made this burglar alarm by himself with a buzzer,clip and a battery. Then he demonstarted how it works. In the mouth of the clip he placed two metal screws . Then he connected one of the screw to the battery and the other screw to the buzzer so that when both the screws are in contact it makes sound . Then he attached an icecream stick to a thread and stuck it on the side wall of the door. He then placed the icecream stick in between the metal screws of the clip and closed the door. When the door opened the icecream stick would come out from the clip and the metal screws would be in contact with each other, so the buzzer would be connected to the battery and makes the beep sound. This is a simple and a wonderful burglar alarm.