Beavers write their name in Morse code. They can use torches in dark or on a sleepover to tell others their name & have other lodges guess who is signalling.
Morse code alphabet, paper, pens
Torches & spare batteries
Provide all Beavers with a Morse code alphabet and a pencil. Ask them to write their name in Morse code.
Signal using torches to other lodges, each person in turn in the dark & try to guess who it is.