When scorpions attack, they deal poison to the opponent, right? So why, when they attack Armigio or any other gravity pulled creature, do they not poison it? It doesn't make any sense.
I suggest that whenever a scorpion attacks, whether it be player or creature, it poisons.
For the case of dune scorpion, unless the snake with neurotoxic bite (can't find the link) card idea is implemented in the game, it should do regular poison damage.