I have noticed a bit of tapping with other species, but nothing like the orchid. The orchid male does it very intentionally, and in a stroking manner. I have often wondered why the female wasn't getting upset and turning around to eat the tiny nuisance. I read it was to remind the female that he is there, which makes sense to me in a way as I have lost a few males during mating because it seemed the female 'forgot' he was there and was startled by him (hence, the constant ducking and moving out of the females field of view in many species), then reached around and gobbled on him. Who knows...