When I once placed a pair together both started shaking their tales too make a loud buzzing ound so as you would guess it was very fast. Moments later they proceeded copulation. They have never done this since the first time i introduced them. Just my experience. I am not to sure in the case of yours though it may be a fluke or somethin else.
WE HAVE AN UPDATE! so today i come in and find the "female" on top of the male as if they were mating... i have watched videos on youtube and it looked exactly the same... but could this be mating if the female was ontop of the male? I have no idea what is going on with these two.