Chiggers live in every US state except Hawaii, but the ones that leave people scratching are concentrated in the warm, humid South, Southeast and Midwest.1PubMed Central. Biology, Systematics, Microbiome, Pathogen Transmission and Control of Chiggers (Acari: Trombiculidae, Leeuwenhoekiidae) with Emphasis on the United States These tiny mite larvae cause most of the itchy summertime bites people get after walking through grassy or brushy ground.2Texas A&M AgriLife Extension Service. Chiggers Region matters less than terrain, because even in chigger country one patch of ground can be crawling with them while the next has almost none.3Orkin. What Are Chiggers? – Learn How to Get Rid of Chigger Mites
Which Parts of the US Have the Most Chiggers
About 248 chigger species have been recorded in the US.4PubMed Central. Biology, Systematics, Microbiome, Pathogen Transmission and Control of Chiggers (Acari: Trombiculidae, Leeuwenhoekiidae) with Emphasis on the United States The greatest variety is in the Southwest, with California at 97 species and Texas at 74.5PubMed Central. Biology, Systematics, Microbiome, Pathogen Transmission and Control of Chiggers (Acari: Trombiculidae, Leeuwenhoekiidae) with Emphasis on the United States But most of those species feed on animals. In Texas, for example, only two of several species are troublesome to people.6Texas A&M AgriLife Extension Service. Chiggers
That is why a long species list says little about your odds of being bitten. What raises your risk is whether the one or two people-biting species are common nearby.
The main biting chiggers are common across the Southeast and Midwest, plus parts of the Great Lakes and the Mississippi River valley.7Orkin. What Are Chiggers? – Learn How to Get Rid of Chigger Mites High humidity and summer warmth in those regions suit them well.8Insect Shield. Where Are Chiggers Found in the US? Western states generally have fewer biting chiggers.9Joshua’s Pest Control. Where Do Chiggers Live?
Fewer does not mean none. Damp, grassy spots such as creek banks and irrigated green areas in dry states can hold chiggers even when the surrounding land does not.
Where Chiggers Hide in the Landscape
The two biting species split the habitat. One favors disturbed grassy and weedy upland, overgrown briar patches and the edges of woods.10Texas A&M AgriLife Extension Service. Chiggers The other prefers moist places such as swamps, bogs, rotten logs and stumps.11Texas A&M AgriLife Extension Service. Chiggers
Moisture and shade decide where they cluster. Chiggers survive best in brushy, grassy or weedy spots that stay a bit moist through the day.12Missouri Department of Conservation. Chiggers Their spread within an area is patchy.13Missouri Department of Conservation. Chiggers They avoid surfaces hotter than about 99°F, so sun-baked rocks are usually chigger-free.14Missouri Department of Conservation. Chiggers A patch that gave you bites is likely to do it again later in the same season, so remember where you were.
Chiggers are ground-dwellers and are rarely found more than a couple of feet up.15Lawn More Gainesville. Spanish Moss Bugs: Fact or Fiction? Spanish moss hanging in trees is therefore very unlikely to carry them.16Lawn More Gainesville. Spanish Moss Bugs: Fact or Fiction? Moss that has fallen to the ground or hangs low against plants can pick them up.17Okefenokee & Satilla Expeditions. Do Chigger Live in Spanish Moss?
How Chiggers End Up on You
The larvae climb grass blades, leaf litter and fallen logs and wait for something to pass.18Romex Pest Control. The Chigger Lifecycle Explained: From Egg to Adult They sense hosts through vibrations and carbon dioxide.19Romex Pest Control. The Chigger Lifecycle Explained: From Egg to Adult Their main hosts are reptiles, birds and small mammals like rodents, with people almost accidental.20Missouri Department of Conservation. Chiggers Brush piles and overgrown cover shelter mice, lizards and other small animals, which is why clearing brush near a home can mean fewer chiggers later.
Larvae grab any exposed skin that touches infested grass or soil.21Defense Centers for Public Health-Aberdeen. Chiggers They dissolve skin cells with saliva and feed through a hardened, straw-like channel.22Ohio State University Extension. Chiggers Bites cluster on the ankles, behind the knees and at the waistband, where they climb up from the ground.23Okefenokee & Satilla Expeditions. Do Chigger Live in Spanish Moss?
A common belief is that chiggers burrow under the skin and live there. They stay on the surface and feed through that tiny channel. The channel can remain in the skin after the chigger is gone, which helps explain why the itch keeps going. Red dots often show up hours after the chigger has fed or been brushed off.
When Chiggers Are Active
Chiggers are most active in afternoons when ground temperature is about 77-86°F.24Missouri Department of Conservation. Chiggers They go inactive below about 60°F.25Missouri Department of Conservation. Chiggers The biting stage dies below about 42°F, so frost ends the season.26Missouri Department of Conservation. Chiggers
Season length depends on latitude. The South can have two or three chigger generations and a season of about seven months.27MyWild. Chiggers in Michigan: Season Dates & Activity Map The northern tier gets one generation and a window of roughly three months.28MyWild. Chiggers in Michigan: Season Dates & Activity Map In Michigan, for example, the typical peak runs about June 25 to August 25.29MyWild. Chiggers in Michigan: Season Dates & Activity Map Consistently hot areas like Texas can see activity for much of the year.30Insect Shield. Where Are Chiggers Found in the US? A cool snap pauses chiggers rather than killing them, so they can return when warm weather does.
On scorching days, sunny ground drives chiggers toward shade. Shady edges stay risky even in the worst heat, so a sun-exposed path is usually safer at midday than shaded brush.
Chiggers in Your Yard and How to Make It Less Inviting
Chiggers are less common in kept lawns.31Pest Me Off. How to Get Rid of Chiggers in Your Yard, Texas Guide But yards backing onto woods, fields or unkept land see chiggers move into the lawn edges.32Lawnstarter. How to Get Rid of Chiggers in Your Yard Ground recently cleared for building can also bring them into plants around a new home.33Pest Me Off. How to Get Rid of Chiggers in Your Yard, Texas Guide
Changing the habitat is the lasting fix. Short grass and trimmed plants raise soil temperature and lower humidity enough to make lawns less hospitable.34Texas A&M AgriLife Extension Service. Chiggers Removing brush and opening areas to light cuts both chiggers and the small animals they feed on.35University of Kentucky College of Agriculture. Dealing with Chiggers in the Landscape Residual sprays with bifenthrin, cyfluthrin, esfenvalerate or permethrin can suppress numbers, and granules usually work less well.36Texas A&M AgriLife Extension Service. Chiggers Spray only the problem edges and patches rather than the whole lawn.
Start with the border strip along woods or fields, mowing it regularly through summer. If you use a spray, follow the label directions exactly.
Avoiding Bites in Chigger Country
Avoid sitting in or near tall grass and weeds.37GardenTech. Identify and Control Chiggers Use insect repellent on clothes and skin.38GardenTech. Identify and Control Chiggers Tucking pants into socks helps too.
Long pants and closed shoes block the ankle route chiggers use to reach your skin. Stay on mowed or cleared trails instead of pushing through brush, and bring a blanket or chair rather than sitting directly on grass or logs. Wash clothes worn in brush in hot water before wearing them again. Chiggers wander on the body before settling at tight spots like waistbands, so showering soon after exposure and scrubbing the ankles and waistline can remove them before they feed.
Is It Chiggers, and Can They Make You Sick
Itch mites cause red welts much like chigger bites, but on the neck, face, arms and upper body.39Illinois Department of Public Health. Itch Mites Itch mite bites usually skip the legs, where chigger bites are common.40Illinois Department of Public Health. Itch Mites
Clusters at the ankles, behind the knees and along the waistband point toward chiggers, though location is one clue among several. See a doctor if bites look infected, with spreading redness, pus or increasing pain, or if you develop a fever after time outdoors.
Chiggers in the US have long been considered not to spread disease to people. A bacterium that causes scrub typhus elsewhere was found in some North Carolina chiggers, which challenges that view.41PubMed Central. Geographic and Orientia infection status influence on the bacterial microbiome of free-living chiggers in North Carolina, USA Researchers are still working out whether it poses any risk to people here.42PubMed Central. Geographic and Orientia infection status influence on the bacterial microbiome of free-living chiggers in North Carolina, USA