# When It Rains: Why Only Earthworms? **URL:** \ **Category:** Factual Questions\ **Created:** [May 3, 2004, 5:44pm UTC](https://boards.straightdope.com/t/when-it-rains-why-only-earthworms/243307 "2004-05-03T17:44:48Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [May 3, 2004, 5:44pm UTC](https://boards.straightdope.com/t/when-it-rains-why-only-earthworms/243307/1 "2004-05-03T17:44:48Z")
Ever notice all the earthworms on the sidewalks and pavements when/after it rains? Correct me if I am mistaken, but like me, you were probably taught they come up for air to breathe since it is displaced by the rainwater. If this is true, why don’t all bugs come out? Consider, if you will, the sign-post up ahead for the (drum roll) cicadas! The little buggers got me re-examining this earthworm thing. How can the cicadas breathe underground for 16 years? Are they totally anaerobic, or something? Or, what about ants? You might say this suggests earthworms require more oxygen than other bugs. But, is this true? (Are they heavier breathers?) What about other bugs breathing underground (consider rainy conditions and the earthworm’s story, esp.) Hmm… It “bugs” me! - Jinx ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 3, 2004, 5:54pm UTC](https://boards.straightdope.com/t/when-it-rains-why-only-earthworms/243307/2 "2004-05-03T17:54:13Z")
Always check with [Cecil](http://www.straightdope.com/classics/a2_014.html) first. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [May 3, 2004, 6:09pm UTC](https://boards.straightdope.com/t/when-it-rains-why-only-earthworms/243307/3 "2004-05-03T18:09:56Z")
Egads! And you thought only humans had a fetish about screwing in public places. At least the folks screwing in the park don’t have to worry about being stepped on! :eek: ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [May 4, 2004, 2:05pm UTC](https://boards.straightdope.com/t/when-it-rains-why-only-earthworms/243307/4 "2004-05-04T14:05:36Z")
a) Of course, earthworms do not breathe as we do; that is irrelevant. The fact is that the water displaces the air. Gas exchange can be performed in so many ways, but if there ain’t no gas to exchange… b) They mate _only_ when it rains? Not to be believed. But, it gives a new meaning to “I hear laughter in the rain…” You’d say I shouldn’t argue with that scientist mentioned in the link provided above, but I think his lab conditions and conclusions fail to completely explain the empirical evidence, IMHO. So, where are the other bugs when the air is displaced? I guess some simply die within a rainy region while their eggs remain unaffected. A new generation soon comes to replace the last. But, this doesn’t explain the cicada’s ability to thrive underground, though. I WAG, if deep enough, perhaps water seeping in from above may also serve to trap some air (i.e.: air pockets) below the surface. - Jinx ---
**Author:** ![wisernow](https://avatars.discourse-cdn.com/v4/letter/w/13edae/32.png) [@wisernow](https://boards.straightdope.com/u/wisernow)\ **Post date:** [May 4, 2004, 2:36pm UTC](https://boards.straightdope.com/t/when-it-rains-why-only-earthworms/243307/5 "2004-05-04T14:36:11Z")
> [@Jinx](#): > > a) Of course, earthworms do not breathe as we do; that is irrelevant. The fact is that the water displaces the air. Gas exchange can be performed in so many ways, but if there ain’t no gas to exchange… Although water replaces the free air, there is air that is dissolved in water that is used by the worms to breathe. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 4, 2004, 2:36pm UTC](https://boards.straightdope.com/t/when-it-rains-why-only-earthworms/243307/6 "2004-05-04T14:36:16Z")
You have to remember that many species of insects can survive for hours or even _days_ while submerged. Some species of ants, for instance, are reported to be able to survive up to 14 days under water. Any insect that lives underground is going to have some survival mechanism to deal with rain and flooding, after all, they wouldn’t be here if they didn’t. ---
**Author:** ![Dead\_Badger](https://avatars.discourse-cdn.com/v4/letter/d/848f3c/32.png) [@Dead\_Badger](https://boards.straightdope.com/u/Dead_Badger)\ **Post date:** [May 4, 2004, 2:44pm UTC](https://boards.straightdope.com/t/when-it-rains-why-only-earthworms/243307/7 "2004-05-04T14:44:01Z")
In my misspent youth I once put a bunch of earthworms in our sandpit when it filled with rain (it was a big plastic thing). They survived for far, far longer than did my attention span, but I was checking on them for about a week and a half and they were perfectly alive for all of that time. Weirdly, they could swim rather well. The only noticeable effect submersion had on them was that they went quite pale, and flattened somewhat. ---
**Author:** ![N9IWP](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/n9iwp/32/3154_2.png) [@N9IWP](https://boards.straightdope.com/u/N9IWP)\ **Post date:** [May 4, 2004, 3:32pm UTC](https://boards.straightdope.com/t/when-it-rains-why-only-earthworms/243307/8 "2004-05-04T15:32:02Z")
Stories on Earthworms [http://www.washingtonpost.com/wp-dyn/articles/A31789-2004Mar28.html](http://www.washingtonpost.com/wp-dyn/articles/A31789-2004Mar28.html) [http://eces.org/articles/000181.php](http://eces.org/articles/000181.php) Until recently, I thought that earthworms were native. Brian ---
**Author:** ![Capt.Ridley\_s\_Shooting\_Party](https://avatars.discourse-cdn.com/v4/letter/c/cc9497/32.png) [@Capt.Ridley\_s\_Shooting\_Party](https://boards.straightdope.com/u/Capt.Ridley_s_Shooting_Party)\ **Post date:** [May 4, 2004, 3:36pm UTC](https://boards.straightdope.com/t/when-it-rains-why-only-earthworms/243307/9 "2004-05-04T15:36:58Z")
Slugs come out when it rains, too. At least I don’t see them as much whe it’s dry.