How can I prevent chiggers?

Control the source of infection: exterminate rats.
Cutting off the transmission route: care needs to be taken to avoid being bitten by scrub typhus larvae, specifically by avoiding activities in infected areas as much as possible; taking care to improve environmental hygiene, such as using insecticides to improve sanitary conditions in field work, cleaning carefully after visiting high-risk areas, etc.; trying not to sit or lie on grass for long periods of time, and taking care to protect yourself when doing field work, such as tightening cuffs and trouser cuffs and applying insect repellent.
Protecting susceptible people: there is no effective vaccine for Orientia tsutsugamushi infection.