Take a vacation to the trenches in France!
Leave blotchy red bite marks over the soldiers bodies!
Carry pyrrexhia or trench fever!
Make it hard for the soldiers to get lice off their clothes and bodies.
The only method that works is the burning candle method but only skilled people can do that.
We won't kill the soldiers but just make it harder to fight with these conditions and pains.
Lice thrive in squalid conditions in which humanity is packed together so we can spread our families rapidly.
Come over to the trenches and you will have the best time of your lice!