I've noticed in a lot of content, especially CT content, monsters and certain targets are immune to Venom Bite. Anyone have a theory as to why say, Ifrit's Nail in Extreme, and the Battle Standards in the new Wanderer's Palace are immune to poison. But Ninja still gets their 20% damage from Poison. And Summoners/Scholars can put diseases on these.

I wish I could ask a developer their logic behind this... "Why is it that I can poison a box of supplies; but the second I want to poison a mechanic I have to kill, it says no?"