An orb in my house?

Or it could be a speck of dust. What do you guys think?

Lena took a series of pictures and this was one of them (that's why its just an aimless pic of nothing, lol). I only noticed the orb after transferring the pics to the computer. And I can honestly say that even though my house does get incredibly dusty, I've never had an orb in a pic taken inside before. So its kinda cool to think that something could have been there (Dad? Ed?) and only showed itself to Lena through the camera.

Or, like I said, it could just be evidence that my house is dirty and I'm slacking off on the dusting. I'm sure that's what Levi prefers to think, else he'd probably never set foot in my house again. HAH!