This could be an all-out symbiote war involving Scream, Phage and other symbiotes, or even the revelation of the existence of Knull,.
In , the female continuously releases a venom that contains a sex pheromone that induces copulatory behavior in males.
The payoff for the cost of physiological resistance is an increased chance of survival for prey, while it allows predators to expand into underutilised trophic niches.