# How do sperm find the egg? **URL:** \ **Category:** Factual Questions\ **Created:** [August 21, 2002, 4:14am UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860 "2002-08-21T04:14:04Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Blalron](https://avatars.discourse-cdn.com/v4/letter/b/35a633/32.png) [@Blalron](https://boards.straightdope.com/u/Blalron)\ **Post date:** [August 21, 2002, 4:14am UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/1 "2002-08-21T04:14:04Z")
It’s not like they have eyes or anything. How do they know where to swim towards? ---
**Author:** ![t-keela](https://avatars.discourse-cdn.com/v4/letter/t/a3d4f5/32.png) [@t-keela](https://boards.straightdope.com/u/t-keela)\ **Post date:** [August 21, 2002, 4:57am UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/2 "2002-08-21T04:57:13Z")
. **How do sperm find the egg?** Usually by accident. 😃 ---
**Author:** ![partly\_warmer](https://avatars.discourse-cdn.com/v4/letter/p/bc8723/32.png) [@partly\_warmer](https://boards.straightdope.com/u/partly_warmer)\ **Post date:** [August 21, 2002, 5:10am UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/3 "2002-08-21T05:10:03Z")
Since they’re limited on brains (trust me, I used to be one), it’s either chemical, a built-in seeking of protected, small places, such as a fallopian tube, or purely random swimming. All these years since my sex ed teacher yelled at me for asking this question, and the answer comes to me… ---
**Author:** ![Tars\_Tarkas](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Tars\_Tarkas](https://boards.straightdope.com/u/Tars_Tarkas)\ **Post date:** [August 21, 2002, 5:11am UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/4 "2002-08-21T05:11:31Z")
They also head for whatever is round and try to fetilize that. (though those might be just defective sperm, as there are videos of them trying to fertilize bumps and blood cells, then getting aten by WBCs) ---
**Author:** ![Blalron](https://avatars.discourse-cdn.com/v4/letter/b/35a633/32.png) [@Blalron](https://boards.straightdope.com/u/Blalron)\ **Post date:** [August 21, 2002, 5:12am UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/5 "2002-08-21T05:12:01Z")
> [@](#): > > All these years since my sex ed teacher yelled at me for asking this question, and the answer comes to me… What kind of sex ed teacher yells at you for asking a perfectly legitimate question about sex? ---
**Author:** ![partly\_warmer](https://avatars.discourse-cdn.com/v4/letter/p/bc8723/32.png) [@partly\_warmer](https://boards.straightdope.com/u/partly_warmer)\ **Post date:** [August 21, 2002, 6:01am UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/6 "2002-08-21T06:01:45Z")
> [@](#): > > \*Originally posted by Blalron \* > \*\*What kind of sex ed teacher yells at you for asking a perfectly legitimate question about sex? \*\* Dear Mz. Frankel, of Berkeley High School, put her face about 2 feet away from mine, and bellowed at the top of her voice. I looked across to the less repressed folks across the room, and a woman I thought was kinda cute shrugged her shoulders sympathetically. I turned around to my best friend, behind me. He figured I’d done something intentionally. No help. Teacher’s face still close enough that if she were a dog, she coulda ripped my face off. Ha, ha. (spoiler follows) It seems my good friend D— B— had asked _exactly_ the same question in a class earlier in the day, and given her a VERY bad time about it. Knowing we were friends, she figured… ---
**Author:** ![Blalron](https://avatars.discourse-cdn.com/v4/letter/b/35a633/32.png) [@Blalron](https://boards.straightdope.com/u/Blalron)\ **Post date:** [August 21, 2002, 6:48am UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/7 "2002-08-21T06:48:05Z")
Compared to the entire female reproductive system, the egg is a small target. It seems logical that something would guide them to the right direction. So do the poor little spermies keep on swimming and swimming blindly until they either fertilize an egg or drop dead from exhaustion? I kind of feel sorry for them. ---
**Author:** ![reprise](https://avatars.discourse-cdn.com/v4/letter/r/ea666f/32.png) [@reprise](https://boards.straightdope.com/u/reprise)\ **Post date:** [August 21, 2002, 6:52am UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/8 "2002-08-21T06:52:59Z")
Now I have this mental picture of sperm swimming around using GPS to find their target… ---
**Author:** ![partly\_warmer](https://avatars.discourse-cdn.com/v4/letter/p/bc8723/32.png) [@partly\_warmer](https://boards.straightdope.com/u/partly_warmer)\ **Post date:** [August 21, 2002, 2:55pm UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/9 "2002-08-21T14:55:12Z")
According to this page, [http://students.biology.lsa.umich.edu/bio208\_4/edev.html](http://students.biology.lsa.umich.edu/bio208_4/edev.html) it’s chemical: "The fusion of the sperm and the oocyte (egg) is known as fertilization. The sperm much first locate the egg by means of chemotaxis meaning the egg is releasing soluble chemicals that attract sperm. " Again, according to that page, the first thing a fertilized egg gets involved with is clevage. Wouldn’t cha know… ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [August 21, 2002, 8:20pm UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/10 "2002-08-21T20:20:40Z")
They don’t “find” it and they are not even looking for it. Rather they are minding their own business when suddenly they are shot in the direction of the egg at very high speed. Some of them can’t help hitting the egg which does not have time to move out of the way. If the sperm are not propelled fast enough then the egg has time to move out of the way and will not be fertilized. ---
**Author:** ![partly\_warmer](https://avatars.discourse-cdn.com/v4/letter/p/bc8723/32.png) [@partly\_warmer](https://boards.straightdope.com/u/partly_warmer)\ **Post date:** [August 21, 2002, 8:26pm UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/11 "2002-08-21T20:26:03Z")
er, sailor, er… how can one put this… how’s your knowledge of female anatomy? It takes several minutes to go along the maze of twisty passages, all alike. [http://www-med.stanford.edu/school/whpu/qa/06,13,98.html](http://www-med.stanford.edu/school/whpu/qa/06,13,98.html) ---
**Author:** ![t-keela](https://avatars.discourse-cdn.com/v4/letter/t/a3d4f5/32.png) [@t-keela](https://boards.straightdope.com/u/t-keela)\ **Post date:** [August 30, 2002, 4:20am UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/12 "2002-08-30T04:20:27Z")
Sailor-"They don’t “find” it and they are not even looking for it. Rather they are minding their own business when suddenly they are shot in the direction of the egg at very high speed. " I think I saw this in a movie…“Look who’s talkin’” or one of those damned sequels…😕 ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [August 30, 2002, 10:48am UTC](https://boards.straightdope.com/t/how-do-sperm-find-the-egg/124860/13 "2002-08-30T10:48:49Z")
I am reminded of a story. A brawl broke out in a bar and several people were injured. Later in the courtroom a lawyer is questioning a witness and asks “Isn’t it true that she was stabbed with a knife in the melee?” to which the witness replied: “Well, the stab was more like half way between her melee and her belly button” 😉