Is it normal for Igs to "Hold their breath"?

[Thunder380Lady]

I sure hope you all aren't getting tired of me asking alot of questions lately, but it just seems like the older Lenore gets, the more things she does that I don't yet understand.
She has recently started "holding her breath".
Is this normal? She does it when I first take her out of her house. She will breathe deep a couple of times, get real puffed, hold her breath for about 10 seconds, then I can feel her body relax and she breathes normal again. She will do this again if something startles her. Just wondered if this is some kind of normal reaction. Also her dewlap flares when she does this.

Karen

[Tesa]

It's a normal thing. I kinda think it's like a big sigh.

Did you know they can hold their breath for more than 20 minutes?

[Merlin]

It's also a way of making themselves look larger and more threatening in hopes that that pesky human will get skeered go away and leave her alone.

Don't buy it! ;D