Caudal movement in snakes may serve either a predatory (e.g., caudal luring) or defensive (eg., rattling, aposematism) function. I describe a new behavioral pattern of tail movement in snakes. Gray rat snakes (Elaphe obsoleta spiloides) foraging on small mammals (Mus domesticus) moved their tails in an erratic, whiplike fashion after detecting their prey in the vicinity. The thrashing movement in the horizontal plane was audibly and visually obvious, resulting in displacement of leaf litter around the tail. All subjects displayed the behavior, but not in all foraging episodes. Shorter durations of caudal distraction resulted in greater predator success during the 1st attempt at prey capture. Caudal distraction may facilitate prey capture by gray rat snakes by direction the attention of prey away from the approaching head of the snake.
Mullin, Stephen J., "Caudal Distraction by Rat Snakes (Colubridae, Elaphe): a Novel Behavior Used when Capturing Mammalian Prey" (1999). Faculty Publications. 115.