# How do mosquitos zero in on prey?
**URL:** https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038
**Category:** Factual Questions
**Created:** [May 2, 2006, 2:08am UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038 "2006-05-02T02:08:12Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@snailboy](https://boards.straightdope.com/u/snailboy)
#### Post date: [May 2, 2006, 2:08am UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038/1 "2006-05-02T02:08:12Z")
So I wake up to go to work in the morning. I do my routine and get dressed. I walk outside, fire up the bike, and start putting on my riding gear. The air is pretty vacant at first, but by the time I take off, I’m fighting off swarming mosquitos comparable to hornets attacking from a nest you’ve disturbed. They seem to just chill out on the ground or somewhere until I walk outside, or get back home in the evening, and then they fly in from every direction. If I get in the car, the ones that don’t get in before I shut the door will fly against the glass until I take off. How in the hell do these blood-thirsty parasites find me so easily? Do they see my motion as I walk by? Do they smell the aroma of mammalian blood? Perhaps they have a tiny alarm system attached to my door. How do they do it?
---
### Author:  [@cerberus](https://boards.straightdope.com/u/cerberus)
#### Post date: [May 2, 2006, 2:11am UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038/2 "2006-05-02T02:11:44Z")
I believe it’s some combination of Carbon Dioxide and body heat…
---
### Author:  [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)
#### Post date: [May 2, 2006, 2:11am UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038/3 "2006-05-02T02:11:45Z")
[“People can attract mosquitoes from 40 miles away simply by breathing. When a person exhales, their carbon dioxide and other odors mix to produce a plume that travels through the air. The plume acts like a dinner bell to mosquitoes, letting them know a juicy meal is within range.”](http://www.cnn.com/NATURE/9908/26/mosquitoes.enn/)
---
### Author:  [@snailboy](https://boards.straightdope.com/u/snailboy)
#### Post date: [May 2, 2006, 2:26am UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038/4 "2006-05-02T02:26:27Z")
Interesting. Maybe I should work on holding my breath. I’m guessing the bike emits more carbon dioxide than I do though, so it would be pointless.
---
### Author:  [@kniz](https://boards.straightdope.com/u/kniz)
#### Post date: [May 2, 2006, 5:04am UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038/5 "2006-05-02T05:04:08Z")
Mosquitos almost refuse to bite me. Everyone around me can be biten several times and at the most I’ll have one bite. I have a condition called COPD, which means that I exhale very small amounts. Could that be the reason? Is my breathing so meager that I’m going under the mosquitos radar? 😛
---
### Author:  [@Max\_Torque](https://boards.straightdope.com/u/Max_Torque)
#### Post date: [May 2, 2006, 2:26pm UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038/6 "2006-05-02T14:26:41Z")
Because they zero in on carbon dioxide, I have heard (but not yet tested, probably will this summer) that one way to keep the mosquitoes off during an outdoor party is to set a cinder block in a far corner of your yard with a few pounds of dry ice on it (the cinder block will keep the dry ice from “burning” the grass). As the dry ice sublimates into CO[sub]2[/sub], the mosquitoes will be drawn to it, and hopefully your guests will be left alone.
---
### Author:  [@AHunter3](https://boards.straightdope.com/u/AHunter3)
#### Post date: [May 2, 2006, 5:54pm UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038/7 "2006-05-02T17:54:37Z")
> [@](#):
>
> How in the hell do these blood-thirsty parasites find me so easily? Do they see my motion as I walk by? Do they smell the aroma of mammalian blood? Perhaps they have a tiny alarm system attached to my door. How do they do it?
I’m pretty sure the various mosquito species have all evolved an **AHunter3** sensor, which registers ever more strongly the closer a given lifeform approximates **AHunter3**. You, for example, end up on the menu because of a sufficient number of gross similarities between you and me.
---
### Author:  [@lieu](https://boards.straightdope.com/u/lieu)
#### Post date: [May 2, 2006, 6:01pm UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038/8 "2006-05-02T18:01:22Z")
I believe I’ve read that it’s only the females that bite and that they can detect temperature variations to a thousandth of a degree. Also, reportedly, a diet rich in garlic may help ward them off.
---
### Author:  [@snailboy](https://boards.straightdope.com/u/snailboy)
#### Post date: [May 2, 2006, 10:03pm UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038/9 "2006-05-02T22:03:53Z")
> [@lieu](#):
>
> I believe I’ve read that it’s only the females that bite and that they can detect temperature variations to a thousandth of a degree. Also, reportedly, a diet rich in garlic may help ward them off.
I know you’re correct about only the females biting. They need the blood for their eggs, not themselves. I didn’t know about the garlic though. I can ward off mosquitos and vampires at the same time. I can’t stand things that suck blood.
---
### Author:  [@spingears](https://boards.straightdope.com/u/spingears)
#### Post date: [May 3, 2006, 2:25am UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038/10 "2006-05-03T02:25:31Z")
> [@snailboy](#):
>
> Do they smell the aroma of mammalian blood? Perhaps they have a tiny alarm system attached to my door. How do they do it?
They respond to CO2 &/or ather attractants.
Google for “mosquito control or traps.”
Lots of products.
---
### Author:  [@AskNott](https://boards.straightdope.com/u/AskNott)
#### Post date: [May 3, 2006, 9:44pm UTC](https://boards.straightdope.com/t/how-do-mosquitos-zero-in-on-prey/355038/11 "2006-05-03T21:44:01Z")
A study published in _Scientific American_ magazine showed that the “hairs” on a mosquito’s snout can sense **warm, moist air.** The flying pattern of a seeking mosquito, once it enters the sweaty heat plume you exude, was compared to that of a torpedo or heat-seeking missile. She’ll go straight until she no longer senses the plume, then she turns until she re-enters the column of warm air. Then she goes straight again. It’s a slow zigzag that eventually takes her to your skin.
If you look down a west-facing brick wall in the late afternoon, you’ll see skeeters flying close to the wall, continually bumping their tiny heads against the bricks. That’s their guidance system misleading them. If a lady skeeter can’t find a blood meal, she can’t lay eggs. However, the successful ones lay enough eggs to make up for the ones who die before laying eggs.