11 common bug bites — and photos to help you identify them

Did you wake up with swollen, red welts on your arm? Or did you come back from a hike with a cluster of itchy bites on your ankles? There are so many types of bug bites that it can be hard to know which one you're dealing with. But identifying bug bites with pictures makes it a little easier.

Trying to identify what kind of critter bit you just based on the reaction on your skin can be difficult, Matt Frye, Ph.D., a community extension educator with the New York State Integrated Pest Management Program at Cornell University, tells TODAY.com.

"The challenge is that human bodies react so differently that it's not (always) possible to look at the results of a bite and determine what caused it," he says.

While some people might get bitten by a mosquito or ant and barely notice, others may develop itchy or painful welts. And, for some, getting a bite or sting can mean a severe allergic reaction that requires medical attention.

When trying to identify the source of a bite, doctors are looking at your skin. But they're also thinking about what you were doing when you got the bite, other symptoms you have and whether or not you got a look a the insect that was responsible, Dr. Amy Kassouf, dermatologist at the Cleveland Clinic, tells TODAY.com.

"We look at patterns and where on the body they were bitten," she explains, like seeing clusters of bites on the ankles from chiggers or a few bites on arms and legs from mosquitoes.

Luckily, most bites are annoying but not seriously harmful for humans, Kassouf says. They tend to be most painful or itchy in the first few days and then heal within a week or two, depending on how much we scratch at them. And you can manage most bug bites at home with oral antihistamines, a cool compress or topical treatments, like hydrocortisone, Kassouf says.

But if you develop symptoms of an allergic reaction — swelling in the mouth, trouble breathing, widespread rash — or signs of an infection, like pus or a fever, you should check in with your doctor, Kassouf says. And bites from certain critters, like venomous spiders or disease-carrying ticks, also require medical attention, she adds.

For bites that aren't necessarily an emergency but aren't going away, your doctor or dermatologist can prescribe other treatments, like topical creams or oral medication, Kassouf says.

Here are some of the mot common bug, insect and spider bites you might be dealing with.

Tick bites

What they look like:

You're not likely to notice a tick bite right after it happens because ticks are so tiny. On top of that, "ticks have factors in their saliva that prevent pain, clotting and an immune reaction,” Frye told TODAY.com previously. “So you may never see any evidence of the tick bite,” he says.

In some cases, people may develop a small, red, itchy bump after a tick bite that's similar to a mosquito bite, the Mayo Clinic says.

And, if the tick was carrying certain tick-borne illnesses — such as Lyme disease or Rocky Mountain spotted fever — they can develop distinctive rashes in the weeks following the bite. Be aware that the rash may not appear on the part of the body where you were bitten.

Other symptoms:

You may develop flu-like symptoms of a tick-borne illness in the weeks after a tick bite. That may mean you have a fever, headache, chills, fatigue, and muscle and joint pain. Some people also develop a distinctive "bullseye" rash.

If you have symptoms like these, you should see a doctor to get evaluated — especially if you know you were bitten by a tick or you recently spent time outdoors in tick-heavy areas.

Chigger bites

What they look like:

Chiggers are small mites that leave clusters of bites. You'll notice that chigger bites are small, red and typically quite itchy. They may look like tiny blisters or pimples or be more like hives, TODAY.com explained previously.

The mites tend to bite along the clothing line, where skin peeks out just above your socks or at the waistband of your leggings. Chiggers might also bite in between folds of skin where it's warmer. You may also develop a rash around the bites.

Other symptoms:

Although chigger bites are painless initially, they become itchy a few hours later. The itchiness is most severe in the first two days and then subsides over the course of a week or so.

With excess scratching, you may develop a secondary skin infection, which can cause swelling and pus.

Bedbug bites

What they look like:

Bedbugs are parasites that feed on human blood. They're most likely to bite overnight or during periods of time when people are immobile, like watching a movie on the couch or taking a long train ride.

But not everyone develops obvious signs of a bedbug bite. For some people, the bites may be so small that they go unnoticed. And for others, the bites can be overwhelmingly itchy, raised red welts that look like mosquito bites or hives.

The bites may appear in a noticeable line — what experts sometimes call a "breakfast, lunch and dinner" pattern, Dr. Benjamin N. Ungar, director of the Alopecia Center of Excellence and director of the Rosacea and Seborrheic Dermatitis Clinic at Mount Sinai, told TODAY.com previously.

And bedbugs can bite any area of skin that isn't tightly covered by clothing. Most often, they bite on the arms, legs and back.

Other symptoms:

For most people, having bedbug bites is similar to having other bug bites. They may be itchy and inflamed for a few days before subsiding and healing.

Some people have such a strong allergic reaction that they’re in danger of developing anaphylaxis, which can be life-threatening. Signs of a more severe reaction include itchiness in areas that weren't bitten, swelling in the lips or tongue and trouble breathing.

If you notice these symptoms along with bug bites, you should seek medical attention immediately.

Spider bites

There are only a few species of spiders in the U.S. that can bite humans.

“The truth is that most spiders are too small to bite us, including those adorable jumping spiders,” Jody Gangloff-Kaufmann, Ph.D., an urban entomologist and coordinator with the New York State Integrated Pest Management community program at Cornell University, told TODAY.com previously.

But there are a few species that, when they bite, can cause serious symptoms.

Brown recluse spider bites

What they look like:

At first, a brown recluse spider bite may look like a bug bite or bee sting. It can be a small, raised red or purplish bump. You may see a tiny pinprick or two fang marks at the area of the bite.

Over the course of a few hours, the skin may start blistering and the red or purplish color can radiate out from the bite site. From there, the venom can cause skin cell death (necrosis), Dr. Melissa Levoska, an assistant professor of dermatology at the Icahn School of Medicine at Mount Sinai, told TODAY.com previously.

Brown recluse bites may cause an area of dead skin that's called an eschar, which typically sloughs off and leaves an ulcer behind.

Other symptoms:

Unlike black widow bites, brown recluse bites aren't painful immediately. But the venom from a brown recluse spider can cause serious skin problems around the area of the bite, which typically become increasingly painful in the hours after the bite.

Black widow spider bites

What they look like:

When a black widow spider bites, it typically causes a painful pinprick sensation. The site of the bite then swells slightly and forms a red rash. You might see two fang marks inside the bite area or a mark that looks like a tiny sting.

Other symptoms:

Black widow spider bites are usually painful immediately. It can also cause swelling, redness, pain and numbness or tingling radiating out from the bite, MedlinePlus says.

And, unlike, brown recluse bites, a black widow spider bite can cause symptoms that affect a large area or the entire body.

When black widows bite, they release a neurotoxin into your body which can cause symptoms such as pain throughout the body, nausea and fever. The symptoms typically begin to worsen within 15 minutes of the bite.

Wolf spider bites

What they look like:

Larger spider species, like wolf spiders, can be a little more aggressive and may bite people occasionally, Gangloff-Kaufmann said. But these bites are typically not dangerous because these spiders are not venomous.

These bites look like raised red bumps.

Other symptoms:

Aside from the bump, you may experience some initial pain at the site of the bite, followed by itchiness for a few days.

Mosquito bites

What they look like:

Mosquitoes leave itchy bumps on the skin that may swell and become red. These reactions typically appear within minutes after a bite, the Mayo Clinic says. In some people, the reaction may look like a painful hive or a blister that forms within 24 hours of the bite.

The bites don't tend to appear in clusters but rather as individual bumps, possibly on different parts of uncovered skin. Some people have more severe reactions that cause a hive-like rash in the area around the bites.

Other symptoms:

Mosquito bites don't typically cause symptoms beyond the annoying, itchy bumps. A severe allergic reaction may come with a hive-like rash, swelling and inflammation of the bite area and swelling around the eyes, the Mayo Clinic says.

Bee and wasp stings

What they look like:

"Bees and wasps are stinging you as a defense," Frye says. "You almost instantly know when you've been stung by one of them because they want you to know right away."

Along with the pain, you will likely notice a raised welt pretty immediately, Kassouf says. You might even see a stinger or pinprick mark inside the bump. Some insects, like wasps, will both bite to hold themselves in place and sting you, Frye says.

People who tend to be more reactive may have severe swelling in the entire limb, and "you can get blisters on top because it's so swollen," Kassouf says.

Other symptoms:

Depending on the exact insect that stung you and how reactive you are to the sting, you may have itching, swelling and pain at the site which tends to be worse in the first few days and then gradually go away, Kassouf says.

Ant bites

What they look like:

When ants bite humans, it grabs the skin and also sprays a compound called formic acid, Frye explains. Ant bites tend to be small, swollen bumps that appear in clusters, Kassouf says.

Fire ants also sting humans, Frye says, which can cause small pus-filled bumps on the skin, according to the Cleveland Clinic.

Other symptoms:

Ant bites are typically painful and itchy. In addition to the bites, fire ants use their stinger to inject a venom called solenopsin, which causes a burning sensation, Frye says.

Lice bites

What they look like:

Lice bites are often easier to identify than other critters on this list because you'll likely see the live lice in hair, Frye says. While head lice and body lice are closely related subspecies, pubic lice are a separate species, he explains.

"They're attached to the hair follicle," Kassouf explains. "They will come down to the skin to feed and bite and then go back." At first, you might just have a few. But as they multiply, you may start to notice the small itchy bites on your scalp or other skin areas, she says.

Other symptoms:

In addition to the lice and their bites, you might notice lice eggs called nits, Kassouf says. Nits are tiny, hard and white, and they stick to the hair follicle.

Body lice can also transmit pathogens, Frye says, which is particularly a problem for people who have poor hygiene, such as homeless populations.

Fly bites

What they look like:

It's not that unusual for flies to bite humans because the female flies need to feed on blood to have the energy to produce eggs, Frye explains. And fly bites may look and feel different depending on the particular species of fly that's biting you, he says.

For example, tiny biting midges may cause very small bites with temporary symptoms that last just a few minutes, he explains. On the other end of the spectrum, horse flies and deer flies use "blade-like" mouthparts to slash the skin before eating the spilling blood, which causes large, painful bites, Frye says.

A fly bite typically looks like a red welt, and "it often has a little center core to it," Kassouf says. "It can look a lot like a bad mosquito bite."

Other symptoms:

Again, the other symptoms you might experience depend on the type of fly that bit you.

For instance, if someone is constantly exposed to black flies, for instance, they might experience headaches, fever, swollen lymph nodes and other symptoms of so-called "black fly fever," Frye says.

This article was originally published on TODAY.com