So yeah, E and C growl. They don't usually do it to express anger or frustration, but sometimes they do. E often growls while he's playing with his animals, so I guess that's not too unusual. But C growls at random times and kind of a lot really. It's pretty hilarious to hear such an intimidating sound come out of that sweet little thing. And when she does it, E exclaims, "Oh! Dura's growling!"
Alls I can say is that these two are surely mine. Once at the dinner table, when I was about 3 or 4 years old, I looked up and interrupted the conversation to announce, in a slow, low growl, "I am the Sectioner!" My parents, understandably creeped out, asked and asked but could never figure out where I had gotten this. Although I'm fairly certain that they couldn't find where it came from, because I am in fact the Sectioner. And apparently so are my kids. We're still figuring out what exactly our roles are as sectioners, but at least we've got the growl down.
We. Are. The Sectioners!