Chiggers, also known as red bugs or harvest mites, are the larval stage of certain mites belonging to the family Trombiculidae. These microscopic pests cause intensely itchy bites, typically after spending time in wooded or grassy areas. The six-legged larva is the only stage that feeds on vertebrates, including humans and pets. They do not burrow or suck blood; instead, they inject digestive enzymes to break down skin cells, which they then consume. While a person can easily bring chiggers inside, the risk of a true indoor infestation is minimal.
Understanding the Chigger Life Cycle and Habitat
Chiggers require specific outdoor environmental conditions to survive and progress through their life cycle. The mites pass through four stages—egg, larva, nymph, and adult—with only the larval stage being parasitic. Adults overwinter in the soil and lay eggs in damp soil or leaf litter during the spring.
The larvae, which are tiny, climb low-lying vegetation to wait for a host. They thrive in areas offering moisture, shade, and dense growth, such as overgrown fields or wooded margins. These conditions maintain the high humidity levels necessary for survival, which are absent in a typical indoor environment.
Once attached, a larva feeds for one to three days before dropping off. It then transitions into a non-parasitic nymph, which, along with the adult stage, feeds on small arthropods and insect eggs in the soil. This requirement for an outdoor habitat, soil, and a feeding host means chiggers cannot complete their life cycle or establish a colony inside a house.
How Chiggers are Transported Indoors
Chiggers can easily be transported inside on people, pets, or outdoor gear. The tiny larvae hitch a ride on clothing or skin after exposure to infested vegetation, such as tall grass or brushy areas. They may wander on the host for several hours, often seeking thin or constricted skin areas like the waistline, ankles, or armpits before they settle to feed.
The transfer window is temporary, as the chigger’s goal is finding a feeding site, not a nesting site. Larvae brought into a home will not survive long due to the lack of appropriate humidity and soil for later life stages. The indoor climate is too dry, and once the larva detaches, it cannot develop further without returning outdoors. They pose no risk of colonizing a home.
Immediate Action and Long-Term Prevention
Immediate action upon returning from a chigger-prone area is the most effective way to prevent bites and stop chiggers from being transported further into the home. Remove all clothing worn outdoors and wash it immediately in hot, soapy water. This process kills any remaining larvae clinging to the fabric.
A hot, soapy shower or bath should follow, with special attention paid to scrubbing the skin using a washcloth or loofah. Prompt and thorough washing can dislodge any chiggers that have not yet attached or begun feeding, reducing the number of potential bites. If bites have already occurred, relief can be found with over-the-counter anti-itch treatments like calamine lotion or hydrocortisone creams.
Long-term prevention focuses on reducing exposure and making outdoor areas less hospitable. When venturing into high-risk areas, wear protective clothing, such as long pants tucked into socks, to physically block access to the skin. Applying insect repellent containing DEET to exposed skin or using permethrin-treated clothing provides an effective chemical barrier against the larvae. Keeping lawns regularly mowed and trimming back dense vegetation also helps reduce the moist, shady habitats chiggers prefer.