How fast are your reflexes?
The following images are four conscutive frames, digitized from a video camera at 30 frames per second, showing a feeding strike by a gaboon viper over a short distance.
I taped this in direct sunlight to get the fastest shutter speed possible. I stepped through the last second before the first frame shown, frame by frame, and there was no sign of movement whatsoever. Not even eyes or tongue.
Note that by the third frame (elpsed time .067 seconds) the mouse is already entirely inside the snake's mouth. The next few frames look similar to the last one shown, as the snake wobbled a bit after completing the strike. Watching the tape at normal speed, you can't even see the motion.
I hope to have time to tape a few other snakes for comparison soon.