Have you ever felt an itch or sting on your skin looked down and saw nothing there? Those pesky bites could be coming from microscopic bugs that are too small to see with the naked eye. As an avid hiker and nature lover, I’ve come to learn about many types of nearly invisible biting insects over the years. Read on to discover some of the most common microscopic bugs that bite humans.
What Are Microscopic Bugs?
Microscopic bugs are tiny insects mites and arachnids that measure just millimeters or micrometers in size. They are so small that they can’t be seen clearly without some type of magnification. Many biting bugs like mosquitoes, ticks, and fleas fall into the microscopic category. Their miniscule size allows them to sneak up on us and bite before we even notice they are there. Knowing how to identify, avoid, and treat microscopic bug bites is an important skill for any outdoor enthusiast.
Common Microscopic Biting Bugs
Here are 12 of the most common types of tiny biting bugs that you need to watch out for
1. Chiggers
Chiggers, also known as red bugs or harvest mites, are only about 1/60 of an inch (0.4 mm) in diameter. The larval stage is the only one that bites humans. After latching onto skin, chiggers inject digestive enzymes that destroy skin cells. This causes small, red, and intensely itchy welts to form. Chigger bites usually occur around the legs, ankles, and waist.
2. Scabies Mites
The scabies mite (Sarcoptes scabiei) is a parasitic mite that burrows into human skin and lays eggs. This causes an extremely itchy rash to develop on the body. Scabies mites spread through direct, prolonged physical contact with an infected person. They can be treated with medicated creams and lotions prescribed by a doctor.
3. Lice
Head lice, body lice, and pubic lice are wingless insects that infest human hair and clothing to feed on blood. They range from 1-3 mm in size. Lice bites cause red, itchy bumps on the skin. Lice spread through close personal contact and are treated with medicated shampoos, combs, and powders.
4. Bed Bugs
Bed bugs are tiny, flat, oval-shaped insects that hide in bedding and furniture. They come out at night to feed on blood. Bed bugs are between 1-7 mm long, while newly hatched nymphs can be as small as 1 mm. Bed bug bites cause clusters of red, itchy welts, often in zigzag lines. They are difficult to eliminate and usually require professional pest control.
5. Fleas
Cat fleas, dog fleas, and human fleas are external parasites that live off the blood of mammals. They reach about 1/16 – 1⁄8 inch (1-3 mm) in length. Flea bites result in small red bumps with a light halo that are incredibly itchy. Fleas can transmit diseases like plague and typhus between animals and people.
6. Bird and Rodent Mites
Bird mites and rodent mites normally infest the nests and burrows of their hosts. When their animal hosts die or abandon the nest, mites will bite humans while seeking a new blood meal source. They are less than 1 mm long and can cause itchy skin lesions. Getting rid of nesting birds or rodents will eliminate the mites.
7. Mosquitoes
Mosquitoes are known for their itchy bites, but many people don’t realize just how small they are. Mosquitoes measure between 3-6 mm which puts them solidly in microscopic territory. Only female mosquitoes bite to obtain blood for egg production. Mosquito bites swell into red bumps that can cause severe allergic reactions in some people.
8. Mange Mites
Mange mites live on the skin of domestic and wild animals. Some types like the sarcoptic mange mite (Sarcoptes scabiei) can infect humans and domestic dogs. Mange mites burrow into the skin, causing intense itching, rashes, and hair loss. Mange is treated with medicated dips, creams, and pills containing insecticides or anti-parasitic drugs.
9. Chigoe Flea
Also called jiggers, chigoe fleas are tiny fleas found in the tropics and subtropics that bury into the skin of mammals. The fleas are about 1 mm long but swell up to pea-size after feeding. Chigoe bites lead to sores that can get severely infected if left untreated. Removing the fleas surgically or with a sterilized needle is often necessary.
10. Thrips
Thrips are slim-bodied insects under 2 mm long that feed on plants. However, they will opportunistically bite humans, especially if disturbed among foliage. Thrips bites feel like a pinch or stab, and they leave behind red, blotchy marks. Applying insect repellent deters thrips from biting.
11. Demodex Mites
Demodex mites are microscopic follicle mites that live on facial hair follicles. Nearly 100% of adults have these mites on their skin. In large numbers, demodex mites may cause rosacea, itching, redness, and other skin irritations. They can be controlled through diligent face washing and doctor-prescribed creams.
12. Chinch Bugs
Chinch bugs are true bugs in the Blissidae family that infest lawns and agricultural crops. They are only about 1/5 inch (5 mm) in size but have piercing mouthparts that can bite. Chinch bug bites feel like a pinprick and can develop into red bumps or hives. Treating lawns with insecticides controls chinch bug outbreaks.
Signs of Microscopic Bug Bites
Here are some common signs and symptoms that may indicate you have been bitten by tiny unseen bugs:
- Small red bumps, welts, or blisters on the skin that are very itchy
- Clusters or groups of bites in zigzag patterns or lines
- Bites concentrated on commonly exposed areas like arms, legs, neck, and face
- Skin lesions, rashes, or hives in localized areas
- Pinprick bites that occur suddenly and cause sharp, stinging pain
- Skin irritation, inflammation, and allergic reactions to bites
How to Avoid Microscopic Biting Bugs
Protect yourself from microscopic pests by taking these precautions:
- Use EPA-approved insect repellent containing DEET, picaridin, or other active ingredients proven to deter tiny biting insects. Reapply as needed.
- Wear light-colored, long-sleeved shirts and pants when outdoors to cover skin. Tuck shirts into pants and pants into socks to keep bugs out.
- Check yourself thoroughly for ticks, mites, and insects after being outside and remove them promptly.
- Keep yards free of tall grasses, bushes, and vegetation where microscopic bugs thrive.
- Install tight window screens on homes to keep out tiny invading insects.
- Avoid sitting directly on the ground when camping, hiking, or in grassy areas.
- Shower and do full body tick checks after potential exposure to microscopic parasites.
- Inspect pets frequently and treat them with vet-approved anti-parasite medications to prevent bringing pests into your home.
Treating Bites from Microscopic Bugs
If you get bitten by tiny unseen biting insects, here are some ways to get relief:
- Wash the bite area thoroughly with antibacterial soap and water to remove allergens and prevent infection.
- Apply a cold pack or ice to reduce swelling, inflammation, and itching. The cold helps numb the area.
- Use OTC anti-itch creams containing pramoxine, menthol, hydrocortisone, or calamine to ease symptoms. Ask a pharmacist for guidance.
- Take OTC oral antihistamines like diphenhydramine (Benadryl) to reduce body reactions to bites.
- Avoid scratching bites as this can worsen irritation and lead to infection. Trim fingernails short if necessary.
- See a doctor immediately if you have severe reactions like difficulty breathing, develop secondary infections, or symptoms don’t improve with self-care. You may need prescription medication.
- For recurring microscopic bites, seek professional pest control guidance to identify and eliminate the source.
Some microscopic bugs can transmit serious diseases, so be vigilant about avoiding bites, get medical care if sick, and protect your home environment against pests. Don’t let miniscule biting bugs keep you from enjoying the great outdoors! With proper precautions, these nuisance biters don’t have to put a damper on your activities.
Q. What could be biting me indoors?
Not many arthropod pests actually infest human skin or clothing. The few that do include:
- Lice. Includes head lice, body lice, and pubic lice. 1-3 mm in length. Feed on blood. Transmitted by close physical contact with another infested person. Head lice live exclusively among the hairs on the head. Body lice, which resemble head lice, live in clothing and are rare in the U.S. except among some homeless populations.
- Scabies mites. These mites are microscopic and feed in human skin. They are transmitted mostly by physical contact with an infected human or pet. Only the human scabies mite (not found on pets) can propagate and sustain infestations in human skin. Not treatable with pesticides applied to the home or bed.
- Hair follicle mites. These are also microscopic mites. However, these mites live in the hair follicles and sebaceous glands of humans. They are considered harmless, or at worst associated with some forms of acne.
Other arthropods that are sometimes found indoors and are capable of biting humans include:
- Fleas. 2-6 mm in length. These are parasitic insects that must feed on blood to survive. Fleas in this country require an animal (non-human) host, such as dog or cat, on which to breed. Bites tend to occur mostly on lower legs.
- Chiggers. Microscopic mites that live outdoors. Only the larval form (smallest life stage) of the chigger mite is parasitic on man. Chiggers are found exclusively outdoors in grass, soil, weedy areas; however itching may not occur for several hours after encountering the mites. Chigger bites are usually concentrated around areas of tight clothing, such as under socks and around waist.
- Bed bugs. Adults reach 5 mm- (1/4 inch-) long. Bed bugs are flattened, oval-shaped insects that hide during day and emerge at night to feed on warm-blooded animals. Human bed bug infestations are increasing in frequency in Texas, especially in apartments and hotels where residents come and go, and where the bugs can move from one unit to another. Nevertheless, they are still relatively uncommon, especially in single-family homes. Bird and bat bugs, relatives of the bed bug, may also be rarely encountered. Bites to humans generally occur only in areas of a structure next to the nesting sites of bats or birds, such as chimney swifts and purple martins. Bed bug bites are painless but can lead to itching and inflammation, and are sometimes accompanied by series of red blotches on the skin.
- Conenose (or kissing) bugs. These are relatively large insects, 10-30 mm- (3/4 to 1/8 inch-) long. They emerge at night to feed on vertebrate blood, but are uncommon in well-constructed homes. Bites occur most commonly on hands, arms, feet, head or other areas exposed during sleep.
- Mosquitoes. These are delicate, generally small (2-4 mm) flies that live mostly outdoors, but can enter homes. Adult mosquitoes feed on the blood of humans, birds and other animals. Most species are active mostly in evenings and mornings. They cause flat, raised welts on exposed skin.
- Thrips. Thrips are minute, elongated insects (1-2 mm long) that feed exclusively on flowers and growing plants. However, thrips occasionally land on skin and bite people, especially outdoors. Thrips bites are a temporary, minor irritation but causes no visible welts or bites. Washing the arms or hands immediately cures a thrips “infestation”.
- Spiders. Spiders are a diverse group of eight legged arthropods. Spider bites are rare, and thus can be ruled out in cases of people with multiple lesions or bites. Individuals vary in their reactions to bites, though spider bites are generally harmless. The only truly dangerous spiders in Texas are the black widow and brown recluse.
- Bird and rodent mites. Minute, 1 mm long mites that can be difficult to diagnose. These mites normally infest rodents and bird nests, but will occasionally disperse from these sites and bite humans. See the following section on mites.
Most of these pests infest homes temporarily and can be controlled via pesticide treatment, or by eliminating the source of the infestation. Arthropod bites are often hard to diagnose without an examination, good description of the bite(s), information about how and when the bites occurred, and (ideally) a specimen of the suspected pest. Although many biting arthropods leave clues that help with diagnosis (such as the pattern and types of lesions), it is often very difficult to determine the cause of a bite with certainty without a specimen or observation of the bite or sting taking place.
Q. How can I get a specimen to help with diagnosis?
To be certain about a diagnosis it is best, of course, to capture the pest in the act of biting; however, this is sometimes not possible. Wiping up a crawling insect and placing it in alcohol is fine for larger specimens. In cases where pests are extremely small or difficult to observe (such as with mites), tape or sticky traps are useful for specimen collection. Use tape to pick up small specimens directly from the skin. Sticky traps are cardboard cards with a glue surface for capturing small crawling insects. They can be purchased through do-it-yourself pest control stores, online, or through pest control companies. Roach hotels, such as are commonly sold in grocery and hardware stores, are also suitable for small specimen collection. Place several sticky traps in areas of the home or office where bites are believed to occur. Along the edges of walls and under and around beds are good locations. Even very small mites can be seen with the naked eye or a 10X magnifying lens once trapped on a sticky board surface.
Many different kinds of harmless insects are liable to be trapped on sticky boards. Field guides with pictures can help with identification and are available in most libraries and bookstores. When identification is in doubt, bring the sticky board to a pest control company or other qualified expert. Samples of vacuum cleaner bag contents, or sweepings, or general collections of dead insects are seldom helpful in diagnosing problems with biting arthropods.
Bug Bite Showdown: Identifying Flea vs. Bedbug Bites
FAQ
What kind of microscopic bug is biting me?
Fleas, mites, and chiggers are bugs that are so small you often need a microscope to see them. These bugs aren’t dangerous. But their bites cause an almost overpowering urge to scratch your skin. Symptoms may include small, raised skin bumps and pain or itching.
What is biting me but I don’t see any bugs?
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Some mites, like scabies mites, are too small to see with the naked eye and can cause intense itching and a rash.
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These tiny flying insects are similar to mosquitoes but are difficult to see and can cause intense irritation.
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Chigger bites are due to infestation with chigger babies (larva) and can be found in grasslands and forests, and around lakes and streams.
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Fleas are often found in homes with pets and can cause itchy bites.
How do I know if I got bitten by mites?
Mite bites on humans are often found in clusters or patches and often itch intensely. They may form small red blisters and if scratched will open and be prone to infection. Mite bites on humans may also cause hives or welts and sometimes cause a hard bump on the skin and swelling.
What are the tiny pinprick bites?
Thrips are tiny (1/16″) straw-colored insects that feed on plants. They have piercing mouthparts for sucking plant juices but can also bite humans. The bite feels like a pinprick. In late summer, huge numbers of these insects may become airborne, landing on people’s clothing and skin.
Do microscopic bugs bite?
Microscopic bugs can still bite. Some of them dig deep into the skin while others only bite on the surface level. The results of these bites can be painful. While the following bugs are microscopic, they can cause serious skin conditions such as eczema and rosacea. 1. Scabies Scabies is one of the most common microscopic bugs that bite.
What causes small spots of skin to sting, like a bug bite?
There are many things that can cause small spots of skin to sting, like a bug bite. Some of the most common causes include: Bug bites: Mosquitoes, fleas, bed bugs, and other insects can all cause itchy, red bumps on the skin. These bumps can sting, especially if they are scratched. Allergic reactions: Allergic reactions to certain foods, medications, or environmental allergens can also cause itchy, red bumps on the skin. These bumps can sting, especially if they are scratched. Contact dermatitis: Contact dermatitis is a skin rash that occurs when the skin comes into contact with an irritating substance, such as poison ivy, detergent, or jewelry. Contact dermatitis can cause itchy, red bumps on the skin that can sting. Insect bites: Insect bites, including those from mosquitoes, fleas, and bed bugs, can sting. The severity of the sting depends on the type of insect and the individual’s sensitivity.
What are the smallest bugs that bite?
Measuring around 0.5mm, scabies are some of the smallest bugs that bite. Symptoms include rashes and red skin, which is the time people with scabies end up at a dermatologist. These small bugs are white-brown and have 8 legs. Careful examination of the infested skin shows scabies, the eggs of scabies, and their feces.
What do bug bites look like?
From ticks to spiders, bees to bed bugs, here’s what the most common bug bites look like. Whether you first notice a sharp pinch, a nagging itch, or a painful sting, discovering a brand-new bug bite is no fun. Some ache, some beg to be scratched, and the worst of the bunch do both.
Are bugs microscopic?
Some bugs have keen camouflage skills so you might think they’re microscopic. They might look like dots, dust, or webbing. Others are so well-hidden that you only see their eggs, poop, or bloodstains after feeding. But truly microscopic bugs can only be seen under microscopes. Mites are a good example, and millions of species exist.
What are the most common bug bites?
Here are some of the common offenders. Mosquito bites are perhaps the most ubiquitous bug bites around. They’re common around the world, with mosquitoes inhabiting every corner of the globe, save for Antarctica. Fun fact: Only female mosquitoes bite.