A few questions about bruxing/chattering

1. Sometimes I play a game with our rat Akira (She's my little brother's rat, but the whole family loves her C: ) where she'll walk to one of my hands, and I'll lightly grab the front half of her body (tight enough for her to have to struggle to get out, but not tight enough to hurt her, I think) and sometimes I'll wiggle my hand to get her excited (and maybe I'll make some noise too), and then if she hasn't gotten loose after a few seconds, I'll let go, and she'll go running right back to my hand. It's cute, hahah. (I hope it doesn't sound like a cruel game. :c)

When we played "rat trap" earlier, I heard her clicking/chattering until I let go, then she stopped. She's never done this when we've played our trap game before. Was she happy/excited? Telling me to be more gentle? I'm assuming that she wasn't freaking out since she always comes back for more and she's never bitten or nibbled me. :T Could it be unrelated to the game? I cleaned off the guest bed earlier today (which had a bunch of my clothes and junk on it) so she had more room to roam.

2. Sometimes we'll click and whistle at her. She used to talk back when we first got her (a little over a month ago), but now she doesn't really do it anymore, except for random clicking, and occasionally in situations like the one above. Any particular reason for this? She's pretty outgoing and friendly, she doesn't strike me as the shy type.

3. Are there any special noises that people can make to rats? Like sounds they like? Sounds they don't like? Our rat doesn't really respond to whistling, and I don't wanna accidentally make some noise to upset her when I'm trying to play. Hahah, I feel silly for asking this.

(I'd make an intro post but I'd rather wait until I have some pictures, and she won't stand still right now. I'll try again later. XP And is this long enough to need a cut? If it does, I'll edit it ASAP)