Chasing shadows

Now, this isn't what i was aiming for this evening, but with the absence of anything better, i quite liked how it looked!!
This is a pic of Mylo being chased by his friend, Levi. Now let me fill in a few missing details- it was getting dark really quite quickly, we were in the shadow of any light that there was, the dogs were travelling at an almighty speed and they're BLACK!!!!!!
I'm certainly not claiming that i planned any of this effect, but then again, the camera is still much cleverer than i am, so perhaps IT planned it!!!!