Many people associate the intense itching from chigger bites with nighttime, leading to the common belief that these tiny arachnids are nocturnal. This misconception often arises because symptoms typically become noticeable hours after exposure, frequently when people are settling down for the evening. Understanding the true behavior of chiggers can help clarify when and how they interact with humans.
When Chiggers Actually Bite
Chiggers do not bite at night; they are primarily active during the day, especially in the afternoon. These microscopic mites prefer warm, humid conditions, thriving when ground temperatures are between 77 and 86 degrees Fahrenheit. They become inactive if temperatures drop below 60 degrees Fahrenheit and cannot survive below 42 degrees Fahrenheit. People typically encounter chiggers when walking through infested outdoor areas during daylight hours. The itching sensation is not immediate; it usually begins several hours after attachment, often between 3 to 12 hours later. This delayed reaction means that by the time the intense itching starts, people may be indoors or in bed, leading to the mistaken impression of nighttime bites.
Understanding Chigger Activity
Chiggers are the larval stage of certain mites, related to spiders and ticks; only this six-legged stage feeds on humans and animals. Contrary to popular belief, chiggers do not burrow into the skin or suck blood. Instead, they attach to the skin, often in areas where clothing fits tightly, and inject digestive enzymes that break down skin cells. This forms a feeding tube (stylostome) through which they consume liquefied tissue, causing the characteristic red, itchy bumps. Chiggers prefer habitats with heavy vegetation, such as tall grasses, wooded areas, and near water sources, particularly in late spring, summer, and early fall.
Preventing and Relieving Chigger Itch
Preventing chigger attachments involves avoiding their preferred environments or taking precautions when in such areas. Wearing protective clothing, such as long-sleeved shirts and long pants tucked into socks or boots, can help create a barrier. Applying insect repellents containing DEET to exposed skin and clothing edges, like cuffs and waistbands, offers protection. Clothing can also be treated with permethrin, an insecticide that kills chiggers on contact; however, permethrin should not be applied directly to the skin. After outdoor activities, promptly showering with soap and water can help dislodge any unattached chiggers.
Once chigger activity has occurred and itching begins, several methods can help manage the symptoms. Applying anti-itch creams containing hydrocortisone or calamine lotion can provide relief. Oral antihistamines may also reduce itching and inflammation. It is important to avoid scratching the bites, as this can lead to skin irritation or secondary bacterial infections. The itching typically subsides within a few days, and the red bumps heal over one to two weeks.