Why Do Mosquitoes Buzz Around Our Ears?

Mosquitoes' Heat-Seeking Behavior

A recent study reveals the fascinating reasons why mosquitoes seem to gravitate towards our ears. Professor Michael Riehle, an entomologist at the University of Arizona, explains that the buzzing sound we hear is merely a byproduct of mosquitoes flapping their wings. The buzzing is most noticeable when mosquitoes fly around our ears because they use heat to locate humans.

When the lights are on in a room, the heat from the light disrupts their ability to sense body heat, causing them to fly around erratically. However, once the lights are off, our bodies become the primary heat source, allowing mosquitoes to pinpoint their targets more accurately. This precision results in a more noticeable buzzing sound.

Female Mosquitoes' Hunger for Blood

Female mosquitoes are the ones responsible for the incessant buzzing. Male mosquitoes primarily feed on nectar, but females require a blood meal after mating to produce eggs. This explains their relentless pursuit of humans, as they're equipped with unique sensory tools to locate their victims.

The Allure of Odor and Carbon Dioxide

Mosquitoes are attracted to strong odors, and our ears are prime targets. While we might not notice the smell of earwax, mosquitoes rely heavily on their sense of smell when they can't locate their prey through heat. This explains why they often buzz around our heads.

Furthermore, mosquitoes are drawn to carbon dioxide, which we exhale heavily near our mouths and noses. Female mosquitoes use sensory receptors on their feet to detect the presence of carbon dioxide, indicating a potential source of blood for their next meal.

The Influence of Blood Type, Genetics, and Diet

While some studies suggest that people with blood type O are most attractive to mosquitoes, Professor Riehle emphasizes that there's no compelling evidence supporting this claim. He believes that other factors, such as genetics and diet, play a more significant role in mosquito attraction.

Our individual body chemistry produces a unique scent that appeals to some mosquito species more than others. Additionally, research has shown that mosquitoes are attracted to men with fewer skin bacteria. This explains why some individuals are more susceptible to mosquito bites than others.

The "Buzzing" Symphony of Mosquitoes

The mosquito's buzzing sound is created by its rapid wing flapping, approximately 500 times per second at a frequency of 450 to 500 Hertz, which happens to be the note "A", the same note orchestras use for tuning. While we perceive it as a high-pitched drone, it's actually a mating call for male mosquitoes.

Male mosquitoes have a higher wing beat frequency than females and are attracted to the buzzing sound of females looking for a mate.

Mosquitoes' Preference for Feet

While we often notice mosquitoes around our ears, Professor Riehle notes that they might actually be more drawn to our feet, which harbor bacteria emitting attractive odors. This is likely the reason we don't notice them buzzing around our ankles.

Studies have found that Anopheles mosquitoes, which carry malaria, are particularly attracted to the bacteria Brevibacterium linens, responsible for the distinctive smell of Limburger cheese.

Summary:

Mosquitoes use heat, odor, and carbon dioxide to locate humans. Female mosquitoes require a blood meal to produce eggs, explaining their relentless pursuit of humans. While some studies suggest that blood type O is more attractive to mosquitoes, other factors, such as genetics and diet, likely play a bigger role. The buzzing sound we hear is a result of the mosquito's rapid wing flapping, a mating call for male mosquitoes. However, mosquitoes are more likely to be drawn to our feet, where bacteria release attractive odors.