Chiggers, the larval stage of the red harvest mite, are usually encountered in late spring and summer in woodlands, pastures, roadside ditches or other areas with tall grasses and weeds. They are also found along lakes and streams, and even in drier places where vegetation is low, such as lawns, golf courses, and parks. They live near the top of grass stems, leaves, and shrubbery and other vegetation. You can find chiggers in damp, low-lying and often-shaded areas, such as meadows, near lakes or rivers, and heavily wooded areas. They are most active during the day, especially when it is dry and sunny.
Adult mites overwinter in soil and other protected places and emerge in spring to lay eggs. The adult female mites lay eggs in the soil, and when these eggs hatch chigger larvae climb up onto vegetation from which they can attach themselves to a passing host human or animal. After the larva is fully fed, often requiring up to 4 days, larvae drop off the host, leaving a red welt, and transform into eight-legged nymphs, which mature to the adult stage. The life cycle is about 2 months, with adult females living up to one year and producing multiple generations.
Young chiggers attach themselves to the skin of people, domestic animals, wild animals, reptiles, poultry and birds. Once on the host, chiggers migrate to parts of the body where clothing fits tightly over the skin such as around the belt line, waistline, and under socks, or where the flesh is thin, tender or wrinkled such as the ankles, in the armpits, back of the knees, in front of the elbow, or in the groin. Chigger larvae do not burrow into the skin, nor suck blood. They pierce the skin and inject a salivary secretion containing digestive enzymes that break down skin cells that are sucked up. Any welts, swelling, itching, or fever will usually develop three to six hours after exposure and may continue for several weeks. Scratching a bite may break the skin, resulting in secondary infections.