BBCtv animation show ostensibly aimed at children. But since it was broadcast around 6pm on Sundays, it became quite a family favourite. Broadcast between 69/11 and 72/11.
They communicated using sounds "quite similar to" a Swannee whistle.
The Clangers are small, pink mouselike persons who live under their planet's surface in caves protected by saucepan lids. The noise of the lids being closed (to protect their home from falling space debris) gave the Clangers their name. The series told of their encounters with iron chickens, seeds, and sentient musical instruments.
They lived on a small, hollow planet far far away, nourished by Blue String Pudding, and Green Soup harvested from the planet's volcanic soup wells by the Soup Dragon.