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Insect 1 is a Tier 1 transmission found in every standard plague and the Neurax Worm DLC. It increases infectivity, with a bonus in countries with a hot climate. It also grants a bonus in mutation chance.

Neurax Worm

In the Neurax Worm DLC, this causes the eggs of the Neurax Worm to attach themselves to insects, also granting an increase in infectivity, particularly in hot climates.