Chiggers are tiny, red-colored pests that cause intense itching and discomfort across North America, especially during the warmer months. These mites are a common source of irritation for many people spending time outdoors.
The Chigger Life Stage That Bites Humans
Chiggers are not insects but are actually a type of mite, which places them in the class Arachnida along with ticks and spiders. Their life cycle includes several stages, but only the six-legged larva poses a problem for humans and animals. This single parasitic stage is nearly invisible to the naked eye, measuring less than 1/150th of an inch in diameter. The adult chigger mites are eight-legged and are harmless, feeding primarily on small arthropods and plant material in the soil.
When the six-legged larva attaches to a host, it does not burrow into the skin or suck blood, which is a common misconception. Instead, the larva injects a digestive enzyme into the skin tissue to break down cells, which it then consumes. This enzyme injection causes the host’s skin to react, resulting in the characteristic itchy, red welt.
Preferred Habitats and Aquatic Environments
Chiggers absolutely do not live in water, nor can they swim effectively. The confusion about their relationship to water stems from their requirement for high humidity to survive. They are highly susceptible to drying out, so they seek out moist environments that help them retain water.
You will commonly find chiggers in dense, overgrown areas that trap moisture close to the ground, such as transition zones between lawns and woods. These mites thrive in tall grass, weedy fields, berry patches, and along the banks of streams or lakes. They simply wait on the tips of vegetation, typically less than a foot off the ground, until a suitable host brushes past to pick them up. Chigger activity is highest in warm temperatures, typically between 77 and 86 degrees Fahrenheit, and they become inactive when the ground temperature drops below 60 degrees.
Immediate Steps After Exposure and Bite Treatment
The moment you suspect exposure to chiggers, the most effective immediate action is to take a hot, soapy shower. It is important to scrub the skin vigorously with a washcloth to physically dislodge any unattached larvae.
To manage the lingering itch and welts, over-the-counter topical treatments are generally recommended. Applying anti-itch creams such as hydrocortisone or calamine lotion to the affected areas can provide relief. Oral antihistamines can also be taken to help reduce the body’s overall reaction to the bite, especially if the itching interferes with sleep. Scratching the bites should be avoided, as this can break the skin and lead to a secondary bacterial infection.