About a month ago, I noticed a perfect cone shaped pile of what looked to be a light colored sand on my front porch (I live in Tennessee). It was under the bottom of the railing, which is a 2x4 about 4" from the concrete floor. The pile was about 2.5-3" high. There was very little clearance above the pile, not big enough for anything but a bug, I would think. I felt the underside of the 2x4 expecting to find a hole, but nothing.

I remember my aunt in Florida telling me that her friend found something like this inside her house. She had been taking a nap, it wasn't there when she lay down. She indicated hers as being 4 or 5 inches high.

This morning I found another one outside on the patio table. This was about 3/4" high. I felt the "sand" that made this and it was gritty, but a little softer than regular sand. Above the pile is a metal pergola with a sunshade made of fabric.

The picture below shows the most recent and smaller pile. I destroyed the shape when I felt the "sand". Not a good shot as it was on a glass top table.

Anyone have any idea what this might be? I'm a little concerned that something might be eating my house.