Are you looking to learn why mosquitoes seem to bite you more often than they bite other people?
Well then, you’re in the right place!
In this guide you’ll learn:
- Why do mosquitoes need blood anyway?
- Why do mosquitoes bite some people but not others?
- What blood type do mosquitoes prefer?
- Why are mosquitoes biting you?
- What are some preventative measures?
Does it seem like the little bloodsuckers have it in for you and you don’t know why?
Before jumping into the why’s and wherefore’s of why mosquitoes do what they do and why they do it to some more than others, we need to understand something about their biology and life cycle. Then we can explore the deeper question of what and why.
There’s a lot of information to cover, so let’s get started!
Ed has been working in the pest control industry for years helping 1,000's of homeowners navigate the world of insect and rodent management. He manages Pest Strategies now helping homeowners around the world!
Table of Contents
Mosquito Overview
Mosquitoes have been around as long as recorded history. They’re annoying little pests that leave itchy bites marks on your skin. They buzz around your head, getting in your mouth, nose, eyes, and ears with an irritating whine that drives people to distraction. And, let’s not forget, they are vectors – carriers – for all kinds of nasty diseases such as malaria, dengue fever, West Nile, Zika, and others. There’s really nothing good to say about them.
Read Also: 20+ Weird Ways People Are Getting Rid of Mosquito Bites
Except for one thing: they are excellent survivors. Mosquitoes exist everywhere in the world in all kinds of climates. There are over 3000 species of mosquitoes in the world with an overall population that is literally unknowable. Researchers estimate, speculatively, there may be over a trillion mosquitoes in the world at the height of their breeding season.
Translation: they’re not on the Endangered Species List and never will be.
No matter how hard we try, we’ll never be able to eradicate them. That means we have to learn to live with them and figure out how to keep them away from us. Before we can do that, we need to know why they’re attracted to us in the first place.
Why Do Mosquitoes Need Blood Anyway?
The reason mosquitoes need blood has to do with their biology and life cycle. Let’s break it down quickly.
Eggs
Female mosquitoes can lay up to 200 eggs at a time. Normally, they lay their eggs in warm stagnant water where there is algae, pond scum, and bacteria.
Those eggs will hatch in about 48 hours or so. Occasionally they lay their eggs above the normal water line on rivers and lakes then the eggs wait several years for a flood to cover them, at which point they hatch.
Larva
The mosquito hatchlings are called larva. They swim through the water by wiggling, earning them their common name: wigglers.
They are aquatic air breathers, which means they have to surface like a dolphin or whale to get a breath of air. They eat algae, scum, and bacteria. They go through several growth stages called instars, getting bigger at each stage.
Read Also: How to kill mosquito larvae?
Pupae
After four to five days they enter their final instar as a pupae. In this stage, they resemble a miniature shrimp.
They don’t eat because they’re in the process of transforming into a winged adult. Instead, they spend all their time tumbling through the water to avoid predators.
Adult
Here is where it gets interesting. Seven to 10 days after the eggs are laid, a fully formed adult emerges from the water and flies off. The males live less than a week, sometimes only two or three days.
They only eat nectar from plants, sugary liquids, or sweet liquids from fruits. They mate with a nearby female and that’s the end of their usefulness. Soon after, they die.
The female also eats nectar and other sweet liquids, the same as the male. After mating though, she needs liquid protein in order to produce her eggs. Mosquitoes don’t have teeth and jaws to chew their food so the only way she can get protein is to drink it by sucking the blood of birds and mammals.
After a blood meal, she’ll rest for several days until she produces a batch of eggs. She’ll lay them in a stagnant pond then go hunting for another blood meal.
Since a female mosquito can live for three to four weeks or more under optimum conditions, she can easily lay over 1000 eggs during her lifetime from that single mating.
What blood type do mosquitoes prefer?
Research shows they have a natural tendency to be attracted to people with Type O blood. Mosquitoes are twice as attracted to Type O blood types as they are to Type A blood types, with Type B blood types falling somewhere in the middle.
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Why Do Mosquitoes Bite Some People But Not Others?
Mosquitoes are no different than any other predator. There are certain things they’re looking for in their prey. If you meet their conditions they’re going to come gunning for you. If you don’t, they’ll ignore you in search of someone else.
Mosquitoes make their choices based on a number of different factors. Scientists are still working to discover what all of them are but they’ve identified some. The ones they’ve identified are:
- Beer
- Blood Type
- Carbon Dioxide
- Clothing Color
- Exercise and Metabolism (Heat and Sweat)
- Pregnancy
- Skin Bacteria
We’ll look at the blood types first since this is the chief determinate for attracting mosquitoes, then briefly cover each of the other items one by one.
What Blood Type Do Mosquitoes Prefer?
Mosquitoes need to drink blood in order to acquire the proteins necessary to produce their eggs, so it stands to reason they’d be a little picky about the type of blood they drink.
Research shows they have a natural tendency to be attracted to people with Type O blood. Mosquitoes are twice as attracted to Type O blood types as they are to Type A blood types, with Type B blood types falling somewhere in the middle.
Mosquitoes prefer blood types in the following order:
- Type O
- Type B
- Type A
Additionally, researchers have discovered that about 85% of people secrete a chemical through their skin that signals what kind of blood type they have. The other 15% of people don’t secrete that chemical. Whether or not people secrete the chemical signal is completely divorced from what blood type they have.
For instance, a person with Type O blood that mosquitoes love, may not secrete the chemical signal so mosquitoes will ignore them, while a person with Type A blood may secrete the signal.
Even though Type A is the mosquitoes least favorite blood type, if that’s what is available, that’s what they’ll drink. So, in our hypothetical scenario, the Type A blood type person will be bitten while the Type O blood type person will be untouched.
It’s just not fair.
Read Also: What’s the best way to use mosquito traps?
Why Are Mosquitoes Biting You?
Let’s take a quick look at the other reasons mosquitoes will be drawn to one person over another.
Beer
Researchers still haven’t pinned down exactly why drinking beer attracts mosquitoes to a person. But all else being equal, drinking a single 12-ounce bottle of beer will make you far more attractive to mosquitoes than someone who doesn’t drink any. If you ever uncover the reason for it, the Smithsonian would like to talk to you.
Carbon Dioxide
One of the main ways mosquitoes finds their prey is by targeting the carbon dioxide on their breath. They can detect it from over 160 feet away. The larger a person is, the more carbon dioxide they exhale and therefore the more likely it is that a mosquito will be drawn to them.
Clothing Color
Jonathan Day, a professor of medical entomology at the University of Florida, reports that dark-colored clothing stands out in a mosquito’s visual range, particularly when the person wearing those colors is moving. Black, blue, and red are the predominant colors that attract mosquitoes.
Exercise and Metabolism (Heat and Sweat)
Lactic acid, which is given off when you’re exercising also attracts mosquitoes. Acetone, a chemical released in your breath when you’re exercising does the same thing, as does estradiol, an estrogen byproduct. Your body heat increases when you’re exercising, which also draws in the mosquitoes. Runners beware!
Pregnancy
Sorry, ladies. When you’re pregnant, your abdomen averages over one-and-a-quarter degrees hotter than the rest of your body. You also exhale more carbon dioxide because you’re breathing for two people. The result is that pregnant women get bitten about twice as often as other people.
Skin Bacteria
A 2011 research study found that bacteria on your skin will convert non-volatile compounds in your sweat into volatile ones that are highly attractive to mosquitoes. Every person has slightly different amounts of skin bacteria as well as different types of skin bacteria.
The type and amount will significantly affect the change in your sweat compounds and how attractive they will be to mosquitoes. This means that two otherwise identical people can be standing side by side and one will be eaten up by mosquitoes while the other is left untouched.
Some of these items are ones you don’t have any control over, but some of them you do. If you like to run, do it in the morning before the mosquitoes are active. Wear light-colored clothing and lay off the beer.
Lose weight. Remember, the larger you are the more carbon dioxide you exhale. As you lose weight, your body mass will decrease along with the amount of oxygen you need. Less oxygen breathed in means less carbon dioxide breathed out. Lose weight and there will be less of you to attract the mosquitoes. QED.
What are some preventative measures?
- Spray on insect repellents that contain DEET are highly effective at warding off mosquitoes. It was developed by the U.S. Army in 1946 to protect soldiers in mosquito-infested areas and has proven to be safe as well as effective.
- Tiki torches and candles with citronella are proven methods of driving mosquitoes away. As long as the flame is burning it will continue to release citronella into the air to protect you.
- Use mosquito dunks to kill larva in the water. Each doughnut-shaped dunk will treat about 100 square feet of water without harming any fish or wildlife. No larva, no mosquitoes flying around your head.
- Essential oils such as lavender, lemon eucalyptus, and tea tree oil are effective, all-natural methods of discouraging mosquitoes and keeping them away from you. There are also a number of repellent bracelets that are wearable means of warding off mosquitoes.
Final Thoughts: Mosquito Bite Preferences
Mosquitoes are naturally attracted to some people more than others. Some of those reasons are beyond your control.
Others are ones you can change quite easily. You can also take some proactive steps to keep mosquitoes away from you so you can still enjoy the summer weather.
