The Flow effect

This seems like a simple objective but after scouring the web I haven’t really seen an ideal solution for this. I’m trying to create a simple flow effect where a movieclip symbol moves along a motion guide and it needs to just start at a designated frame (without any mouse events) and then continually initiate so it creates an effect like ants following each other in a line. I’m not sure of the best way to do this that won’t tax the processor to heavily and whether to use a hittest with an iteration loop to attach movieclip or duplicate movieclip, etc. I figure it would be nice to use a hittest because then you could adjust the timing of the flow increment. I’m no actionscript expert so if you want to slap some code down please do. I’ve attached the .fla file (CS3) for reference. Is there an easy AS2 solution for this?

Thanks in advance.