I have to admit this image had me stumped for a bit. My initial train of thought was that it had to be moving fairly fast because not only is it in the foreground,but if you look you can faintly see the enomoly moving into the other room and past the opening on the left.
For it to move that quickly it would have had to move at phenomenal speeds!
UNTIL!
I started looking at the EXIF data. EXIF data really tells the whole story. A few key factors to notice is that it was a flash photograph (Flash: fired) and that it was at a low F-Stop setting (3.
and also and most importantly that the exposure time was 4 SECONDS.
So that means everything we're seeing in this image happened over a 4 second period of time. The program on the camera was a Creative Program of type "Night Scene". Generally those type will fire the flash over a 500ms period with a spread fire, and then keep the exposure going to get the highlight detail.
So lets look at the sequence of events:
1) The flash started firing at T-0000ms.
2) A small bug fairly fast bug was caught in front of the camera on the right, and was startled by the flash.
3) The bug started erratically flying away, perhaps hit something and then zoomed downward and into the other room.
As the bug got farther away from the flash you can see it gets dimmer and dimmer. Seems impossible until you remember that it all took place over 4 seconds. Count "1 one-thousand... 2 one-thousand"... and see how long that really is. Plenty of time for a bug to make its mad dash.