Glowing beetles send messages
A firefly is a small beetle that makes its own light in its body. It does not need a lamp. A firefly flashes in a pattern, and other fireflies of the same kind see the flashes and answer. The flashing is a signal. People and animals send and receive information with signals. A signal can be light, such as a traffic light or the flash of a lighthouse. It can be sound, such as a bell, a horn or a bird’s call. It can be movement, such as a wave or a thumbs up. Every message has a sender, a signal and a receiver. The sender chooses a signal, the receiver senses it with the eyes or ears, and the brain understands it. If sender and receiver do not know the same code, the message is not understood. We cannot draw a firefly’s glow honestly, so we imagine it from the words.
What do I know about messages? Make a three-column chart: Know, Want to know, Learned. In the first column write three ways people send messages (a phone call, a letter, a wave). In the second write two questions. After this unit, fill the third column. Then send a message to a friend across the room using only a movement or a coloured card. Did the friend understand?