Me again, with another silly question. When I tried to move my 10 month old Diamond off the thermometer tonight (she’s in a new enclosure and I’m trying to adjust the temperature) she got in a defensive position and then made a sound that started off as a whistle and then became a hiss. This is the first time that I’ve heard her make any noise whatsoever. A few weeks ago I was watching a video in which a woman talked about her 18 month old Diamond learning how to hiss but only managing whistles. I didn’t think about it again until tonight, so I tried to Google if there’s any truth to what she said about juveniles having to learn how to hiss, but no luck. Plenty of hits about hissing, or whistling being possible sign of RI, but nothing that answered my question. I tried to provoke her into making that sound again, but she wouldn’t do it. So is there any truth to that woman’s claim that juveniles need to learn how to hiss, and only manage whistling at first?