chick noise?

[TinyLittleFarm]

What is this cute little squeaky noise the chicks are making? It almost sounds like they are purring. We notice it when they are being held and are not chirping. Is it a pre-cluck? I assume it's normal?

 

[catdaddy66]

Mine did it and still do at 4 weeks old. Chickens have many different sounds/timbers/pitches that they use for communicating. Many animals do as well, including dogs (10 sounds) and cats (100 + sounds).