Some pests live off blood from humans and organisms, others consume skin cells, and still others only bother humans when they’ve been disturbed themselves. Knowing how to treat bug bites is easiest when you can identify them by the bite’s appearance, the anatomy of the species, and by being aware of what pests are in your environment.

While most bites from pests bring only minor discomfort, some are painful, and a few are deadly. Along with headline-grabbing illnesses like Lyme Disease, Rocky Mountain Spotted Fever, Zika, and West Nile Virus, the medical community has seen severe allergic reactions to different insects and arachnids.

While certain pest bites lead to disease and viral infections, the greatest risk in many cases is a secondary infection from scratching the affected area. Use this bug bite identification guide to learn about and identify the most common bites and stings from wildlife in North America.

Fire ants

Identifying fire ant bites

A wound from a fire ant is obvious right away. You’ll likely find a red lesion, sometimes with pus, along with welts or lumps. Blisters appear a day or two after the sting and remain up to eight days, sometimes causing scars. Swelling in the area is also common.

In most cases, a fire ant attack means multiple wounds. These ants react aggressively when their large mounds are disturbed. Ironically, multiple wounds often come from the same ant. When this happens, you may see a semicircular pattern in the affected area where the ant has pivoted its head while attacking.

Symptoms of a fire ant bite

You may feel a sensation like burning or stinging – because, like with bees and wasps, a fire ant attack is a sting rather than a bite. Even though it uses its jaw to latch onto the skin, it stings (injects venom) with its abdomen.

Fire ants look much like carpenter ants and other varieties you may know well. Reddish brown to reddish black, you will find their dirt mounds in sunny areas. Originally from South America, they have been in the U.S. since the 20th century and have become common in the South, although they still may be migrating northward.

Treatment of fire ant bites

Discomfort can be relieved with antihistamines and pain relievers, as well as cold compresses. Do not scratch the skin or puncture blisters to prevent secondary infections. Keep blistered areas clean with mild soap and water.

As with bees, a few people have toxic or even life-threatening allergic reactions to fire ant stings. Seek medical attention if you experience nausea, diarrhea, sudden anxiety, dizziness, sneezing, wheezing, excessive swelling, itching or swelling in the face, chest tightness, or trouble breathing.

Bed bugs

Identifying bed bugs

When bed bugs bite – and even when one bites multiple times – it’s common not to notice the area for a few days.  Their saliva has anesthetic properties which promote blood flow at the site. Along with swelling and/or a red rash, it is common to find itchy red welts that can be small, flat or raised. You may also see a tight line of small red marks.

Reddish, shaped like apple seeds, and under a millimeter, these bugs aren’t found only in bedding. They often live in old furniture and cluttered areas, but they can also be transferred into cleaner environments via luggage, boxes, and pets.

 Symptoms of bed bug bites

If you do have a reaction, the first thing you may feel is a sensation and then itching. While bed bugs can bite humans anywhere on their bodies, most bites occur on uncovered areas like the neck, face, arms, and hands.

Treatment of bed bug bites

Bed bugs feed on other organisms like humans every five to ten days. Nevertheless, they do not carry disease, and for most people, the greatest risk is infection from scratching. Some individuals do experience a mild or severe allergic reaction to bed bug saliva within one to three days. If you see hives, visit your doctor. Otherwise, relieve the itching with over-the-counter cortisone creams and antihistamines.

Bees and wasps

Identifying a sting

In individuals without bee and wasp allergies, the evidence of a bee or wasp sting is generally a swollen, red welt and a small white spot along with sharp, instantaneous pain. Honey bees also leave their stingers behind. While bees die shortly after stinging, wasps survive because their stingers are not barbed and are not pulled out of their bodies.

Treating bee stings

If you spot a bee stinger on the surface of the affected area, quickly remove it with tweezers.  Wash with soap and water to remove all traces of venom infection, and clean it with antiseptic. If you apply antibiotic ointment, make sure the area is thoroughly dry. The pain can be relieved with a cold pack. You can take over-the-counter remedies like antihistamines and nonsteroidal anti-inflammatories.

Treating wasp stings

Many wasp stings cause pain and swelling. This can be reduced by wrapping the area in a cloth for 20 minutes every hour. If you haven’t had a tetanus shot in a decade, you will need a booster shot within days after a wasp sting.

If you know that you are allergic to bees or wasps – or experience a weak pulse, trouble breathing, dizziness, fainting, or swelling of the throat and tongue, call 911.  If you have an epinephrine injector pen nearby, use it immediately.


Identifying chigger bites

Small, itchy red bumps are but one sign that a chigger has bitten you. You may notice a bright red dot in the center of the inflamed area—this is a remnant of the tube your skin formed in response to the chigger’s saliva. These bumps appear in groups and may look like welts, blisters, hives, or even pimples.

While many pests attack exposed areas of the body, chiggers seek out warm areas where clothing fits tightly on the skin. Most chigger bites are found near the ankles, waist, armpits, crotch, and armpits, and folds of skin like armpits and the backs of knees.

Barely visible to the naked eye, chiggers are a type of mite that bites humans when they are still larvae. Under 1/150 of an inch at this stage, you can spot their red bodies when they group together. Once they consume human skin cells, the red color fades to yellow.

These arachnids live in wooded areas and tall vegetation. They can attach to humans who make contact with weeds and brush. Chiggers inject their saliva, which enables them to liquefy and eat skin. They can stay attached and feeding for several days before falling off. The bite itself is not painful, and the discomfort is highest within two days afterward. Nevertheless, they do not feed on blood and do not carry disease.

Treatment of chigger bites

Treat chigger bites with over-the-counter itching remedies so that you do not scratch and risk infection. The discomfort is most intense within the two days after the bite, when the chigger falls off. If there does seem to be an infection, or if the welts spread, visit a doctor.


Identifying flea bites

Flea bites are usually found in groups of three or four, often as a rash of small, red bumps that sometimes bleed. Characterized by reddened circles around red spots, flea bite rashes turn white when they are pressed and often grow or spread over time. Fleas tend to target legs, ankles, armpits, elbows, and the area behind knees.

These reddish brown insects are about 2.5 millimeters long and jump wide distances. They suck blood from their host to feed. In rare instances, the U.S. has seen cases of plague which fleas spread to humans between rodents and pets.  However, fleas are largely harmless.

Treatment of flea bites

See a doctor right away if the wound begins to excrete pus — a few individuals experience allergic reactions when fleas bite them. Otherwise, flea bites can be easily treated with over-the-counter hydrocortisone creams or antihistamines. Scratching the rash can lead to a skin infection, so it is important to address itches. Once you have an infestation in your home, you will need to vacuum daily, spray insecticides, use a veterinarian-approved insecticide on pets and keep those pets out of bedrooms.

Deer flies

Identifying deer fly bites

While most flies are simply annoying pests, a deerfly bite must be carefully treated. You’ll find an itchy red bump or welt with swelling around the bite, which is noticeably painful. These insects are active on sunny days and can be found around forests, beaches, lakes, and other damp areas.  The same size as houseflies, deer flies have patterned wings and black or yellow striping.

Symptoms of tularemia

One American deer fly species is known to transmit the disease tularemia, a severe bacterial infection that can be fatal to both humans and animals if not treated with antibiotics. Seek medical attention right away if you have ulcers, a headache, exhaustion, chills or fever, headache, exhaustion, or swollen and painful lymph glands.

Treating most deer fly bites

Deer bites can be treated with soap and water, antihistamines, and cold packs. When the flies are blood feeding, they inject saliva that contains anticoagulants, which sometimes cause an allergic reaction. Seek medical attention right away if you are wheezing, if your lips or your eye area swell, or if you feel dizzy or weak.


Identifying mosquito bites

A mosquito bite is generally a raised surface – often a round or even hard skin bump that becomes irritated quickly. It can be puffy with a red dot in the middle and may appear as small as blisters. Mosquitoes feed on blood to cultivate their eggs.

Symptoms of mosquito bite-related illnesses

It is common for children to experience low grade fever or swelling after being bitten.

While life-threatening diseases like malaria aren’t first-world issues, the Zika and West Nile Viruses have affected many people in North America. There has even been a reported case of chikungunya virus in the U.S.

If you have head or body aches, fever, diarrhea, or vomiting within two weeks of being bitten, seek medical attention to be sure that you do not have the West Nile virus.

Many people affected by the Zika virus have mild or no symptoms, and this infection often means only a brief, flulike illness for most patients. Nevertheless, there is a significant rate of microcephaly in infants born to Zika-infected pregnant women. Consult a doctor if you develop a rash, a headache, pain in joints or muscles, or conjunctivitis.

Treating mosquito bites

In most cases, the main concern is a secondary infection from scratching. These infections can lead to a secondary infection, which can pave the way for illnesses like staph, strep, or impetigo. This makes it very important to apply a topical hydrocortisone cream. A large number of bites – or symptoms like swelling or hives – calls for an antihistamine.

Black widow spiders

Identifying black widow spider bites

Two fang marks are a distinctive sign of a black widow spider bite, along with a tender, red wound and a nodule where they have bitten. While the bite itself is not always painful, it is often followed by a spike in blood pressure, muscle cramps, nausea, vomiting, and/or a seizure 20 minutes to an hour afterward. Black widow bites are also known to cause radiating pain, abdominal cramping, and excessive sweating,

With long legs, a glossy black abdomen, and a distinctive red, yellow, or orange hourglass shape on its underside, the black widow herself is easy to spot. They often take cover in wood piles, tree stumps, and sheds and are found mostly in the Southern and Western U.S.


Treating black widow spider bites

If you are bitten, seek medical attention immediately so that you may be treated with antivenin. Call 911 or the American Association of Poison Control Centers at 800-222-1222. If you can, bring the spider with you to the ER for positive identification.

Brown recluse spiders

Identifying brown recluse bites

Although a bite from a brown recluse spider may not be painful – and you may not even realize it for some time – it can cause infection and illness. In a few cases, its venom can be deadly.

Its bite often begins first as a red spot, with reddening and swelling. This area often whitens and develops a painful blister shaped like a bull’s eye.  It could appear blue-purple and resemble a bruise, or even darken later and become crusty.

Brown recluse spiders have a distinctive dark violin-shaped markings and vary in color from dark brown to light tan.  True to their name, they inhabit secluded areas like attics and closets and underneath leaves, rocks, woodpiles, or structures. They are normally found in the South and Midwest.

Symptoms of brown recluse bites

It is common to feel severe pain at the wound site several hours later, followed by intense itching, muscle pain, nausea, vomiting, and fever.

Treating brown recluse spider bites

See a doctor immediately if you think you have been bitten by a brown recluse. Some people have serious reactions that result in kidney failure, seizure, or coma.  You can call 911, and you can also seek help for poisonous spider bites from the American Association of Poison Control Centers at (800) 222-1222. If you can, bring the spider to the ER for proper identification.


Identifying tick bites

The first time you notice a dime-sized red spot, it can look like another kind of pest bite. A tick’s bite may have a black dot in the middle. If the head and mouthparts remain in your skin, you may notice a larger black mark, or sometimes even pincers. Sometimes a hardened bump is underneath the punctured skin.

Ticks are often found in plants and brush and often bite humans and animals. When they attach to humans, they tend to seek out warm and covered areas like skin folds, the groin, the scalp, and hair-covered areas.

Tick bites often go unnoticed unless the insect is still on the skin, sometimes even burrowing into it. If it falls out cleanly, this bite should heal without any other problems. But a tick remaining without being carefully removed risks infection or, depending on the type of tick, an illness like Rocky Mountain Spotted Fever or Lyme Disease. Like other pest bites, some individuals also experience allergic reactions after being bitten by ticks.

Symptoms of Lyme disease

If your rash is red and circular – and expands – seek medical attention immediately. The so-called “bull’s eye” rash may be accompanied by fever, chills, fatigue, headache, aching muscles or joints, or swollen lymph nodes – symptoms of Lyme’s disease.  A black-legged tick (also known as a deer tick) must usually be attached 36-48 hours to spread this disease. It can damage your joints, heart, muscles or nervous system if not treated.

Symptoms of Rocky Mountain Spotted fever

A rash that begins on the ankles and wrists after a few days of fever, but later spreads to the rest of the body, is a possible sign of Rocky Mountain Spotted fever. Head and muscle aches are also common symptoms. Caused by dog ticks, this potentially fatal infection can be treated with prompt medical care.

Treating tick bites

Regardless of the type of tick, wound appearance, or symptoms, it is important to remove the pest from your skin to prevent further infection.  Cover the tick with petroleum jelly or hold something hot close to it so it cannot breathe. If it doesn’t let go, use fine-tipped tweezers to grasp its body as close to your skin’s surface as you can. Pull upward with steady, even pressure. Clean the bite area carefully with iodine, alcohol, or soap and water. If the tick’s mouth remains embedded in your skin, leave it alone and allow the skin to heal.