It indeed looks like finely ground vermiculite doing an Internet image search. I'll have to look up in the wall cavity and see what I can see. The wall is an outside wall in the kitchen. Single story. I should mention, though, that this part of the kitchen was added on at an unknown time. We certainly have wind and dust. However, this doesn't look like our normal Oklahoma dust. Our dust is much more red. On the 40 MPH wind days in the summer, the sky is brown. Just like the Dust Bowl in the history books! Luckily for us, we have much more concrete than we did back then, so the dust isn't as bad. Haha We also have fire ants, but I haven't noticed any signs of them on the 4.75 acres that I own. However, this place has been around a long time and has been surrounded by open Indian land for (100s?) of years, so it doesn't mean that there weren't fire ants before! But, this stuff seems too consistent - man made. I think if it were indeed critter caused that it would have more dirt and other particles, too. I'm feeling confident that it's vermiculite. Insulation was my very first guess when it came pouring out of the wall. Haha But it was just a very strange sight. Guess I'll let it all flow out since I'll be dense packing cellulose in all the wall cavities sometime soon.