have a ~6-7 wk quail and i sometimes hear a very weird sound. almost like low pitched duck quack but i dont phyiscally see any of them moving their mouths so I can't tell who. also, one of them she/he (not sex'd yet) is acting slightly aggressively and i suspect it's that one. when one of them does make this sound, they ALL go nuts as if there is danger. (i have 5 of them total).