# Do all animals require water to live? **URL:** \ **Category:** Factual Questions\ **Created:** [January 22, 2003, 2:15am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127 "2003-01-22T02:15:15Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [January 22, 2003, 2:15am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/1 "2003-01-22T02:15:15Z")
Channel surfing, I caught a show on “Animal Planet” about desert life in the Sahara. One fox-like animal, a fennick, can live its whole life without taking water! Yet, isn’t water a staple for all animal life? I WAG the animal takes in water only from the water content of the flesh of its prey? I’m going to get a drink… - Jinx ---
**Author:** ![Lissa](https://avatars.discourse-cdn.com/v4/letter/l/85f322/32.png) [@Lissa](https://boards.straightdope.com/u/Lissa)\ **Post date:** [January 22, 2003, 2:18am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/2 "2003-01-22T02:18:14Z")
They must have water in one form or another. And yes, a lot of animals don’t get a lot of liquid water, they get their water from their food. Lions in Africa, sometimes kill just to lick the blood of their prey, because of their thirst, and the lack of watering holes. Fennels are probably the same way. ---
**Author:** ![Mr.Duality](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mr.duality/32/4098_2.png) [@Mr.Duality](https://boards.straightdope.com/u/Mr.Duality)\ **Post date:** [January 22, 2003, 3:19am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/3 "2003-01-22T03:19:06Z")
Prairie dogs have that trait. Human food can be moist enough to make them sick. Sorry, no cite. I got that info from a flyer distributed by the National Park Service at the entrance to Devil’s Tower National Monument. [http://www.ngpc.state.ne.us/wildlife/pdogs.html](http://www.ngpc.state.ne.us/wildlife/pdogs.html) ---
**Author:** ![Stan\_Doubt](https://avatars.discourse-cdn.com/v4/letter/s/53a042/32.png) [@Stan\_Doubt](https://boards.straightdope.com/u/Stan_Doubt)\ **Post date:** [January 22, 2003, 3:46am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/4 "2003-01-22T03:46:07Z")
Yes, there are several animals that can survive despite never drinking fresh water, desert rodents and marine mammals are good examples. A simple explanation for obtaining water from food is the reaction that takes place when most carbon-containing molecules are burned. Whether in your digestive system or in an automobile engine, byproducts include carbon dioxide and water. These animals also may have specialized kidneys to make very concentrated urine, i.e., waste very little water to eliminate lots of nitrogen. ---
**Author:** ![Motog](https://avatars.discourse-cdn.com/v4/letter/m/85e7bf/32.png) [@Motog](https://boards.straightdope.com/u/Motog)\ **Post date:** [January 22, 2003, 4:32am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/5 "2003-01-22T04:32:25Z")
Koalas are another animal that never drinks FWIW ---
**Author:** ![SnugTheJoiner](https://avatars.discourse-cdn.com/v4/letter/s/e8c25b/32.png) [@SnugTheJoiner](https://boards.straightdope.com/u/SnugTheJoiner)\ **Post date:** [January 22, 2003, 4:36am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/6 "2003-01-22T04:36:05Z")
When I was a kid I read that the kangaroo rat never drinks water, but gets all the moisture it needs from the seeds, etc., that it eats. However, I read this in a Disney nature book (“The Living Desert”), and the Disney people once threw lemmings off a cliff to make a nature film, so take it with however much salt you think appropriate. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [January 22, 2003, 5:14am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/7 "2003-01-22T05:14:50Z")
> [@](#): > > \*Originally posted by SnugTheJoiner \* > \*\*When I was a kid I read that the kangaroo rat never drinks water, but gets all the moisture it needs from the seeds, etc., that it eats. > \*\* Kangaroo rats are capable of going without water by getting the water out of their food. _Britannica_ says: " They seldom drink water, obtaining sufficient moisture from their food." However, they will drink when it is available and they happen to be thirsty… ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [January 22, 2003, 8:07am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/8 "2003-01-22T08:07:16Z")
Lot’s of animals never need to drink. As Cecil says, humans are theoretically capable of it even on a diet of nothing but bread. People have lived without drinking for considerable lengths of time, although in these cases they were sucking the fluids out of fish. But then that’s all that the fennec fox does really. Basically so long as an animals has food with sufficient moisture in it then it never needs to drink. A few species of desert rodents are unique amongst land mammals in that they can live on totally dry food. That is seed that has had all the moisture removed. These little critters get away with it because simply digesting food will produce water. Unfortunately for most mammals the act of digestion also increases heat and the amount of oxygen used. This causes the body to lose water as vapour in the breath, and also in an attempt to cool down. The kangaroo rat has a small enough nose that the water in the expelled breath can be recollected in the sinuses before it is lost. Meanwhile living underground and operating only at night means that heat stress is never an issue. Of course lots of reptiles and insects and things never need to drink, but they get way with it by having different methods of coping with excess salt. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [January 22, 2003, 8:22am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/9 "2003-01-22T08:22:49Z")
> [@](#): > > \*Originally posted by Blake \* > \*\* > A few species of desert rodents are unique amongst land mammals in that they can live on totally dry food. That is seed that has had all the moisture removed. \*\* A chemist or maybe to be more exact a food chemistry specialist and probably straighten this out. My understanding is that the kangaroo rat, for example, uses the water contained in the hydrates (remember the [sup].[/sup]H[sub]2[/sub]O?) of their food. The food can not have any free moisture, if that’s the right way to say it, and still have lots of water of hydration that the animal can use. ---
**Author:** ![Andy](https://avatars.discourse-cdn.com/v4/letter/a/aeb1de/32.png) [@Andy](https://boards.straightdope.com/u/Andy)\ **Post date:** [January 22, 2003, 8:26am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/10 "2003-01-22T08:26:16Z")
IIRC, about a third of our water requirement comes from water, the rest needs to be contained in our food. ---
**Author:** ![everton](https://avatars.discourse-cdn.com/v4/letter/e/ecb155/32.png) [@everton](https://boards.straightdope.com/u/everton)\ **Post date:** [January 22, 2003, 8:46am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/11 "2003-01-22T08:46:52Z")
I can’t believe there are two threads about that TV programme. [feneq?](http://boards.straightdope.com/sdmb/showthread.php?threadid=157534) ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 22, 2003, 9:10am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/12 "2003-01-22T09:10:52Z")
I used to keep gerbils and I never once gave them liquid water (and no, they didn’t die!) - they would eat about half a slice of cucumber (or similar) each every couple of days - in the wild, the only liquid water they are likely to see is dew so they get nearly all of their liquid intake from the bodies of insects and from fruits. I heard somewhere that some desert rodents store seeds in the entrance of their burrows; some of the moisture expelled in the rodent’s breath condenses on the seeds and is absorbed, so the animal gets it back later when the seeds begin to sprout and are eaten. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [January 22, 2003, 11:18am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/13 "2003-01-22T11:18:05Z")
Dave that’s pretty much what I said. The grain is totally dry. No moisture. Chemically bound water is not moisture, nor is it water. It only becomes water after it’s liberated through digestion. A lot of rocks also contain chemically bound water, but there’s no way anyone is going to say a rock is wet. (Unless it is of course.) ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [January 22, 2003, 9:15pm UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/14 "2003-01-22T21:15:05Z")
Blake, I can’t tell what you were saying in your first post, but it doesn’t look like what David was saying. Water of hydration is not “chemically bound,” it’s physically bound. Some materials include water in their crystal structure. Such materials rarely appear moist, yet they most certainly contain water. What you appear to be describing is a metabolic process in which hydrogen liberated from organic compounds combines with oxygen to form water. I don’t know if this happens, but it seems unlikely to be a suitable source. Forgive me if I’ve misunderstood you, but you haven’t been entirely clear. ---
**Author:** ![X\_Slayer\_ALE](https://avatars.discourse-cdn.com/v4/letter/x/bbe5ce/32.png) [@X\_Slayer\_ALE](https://boards.straightdope.com/u/X_Slayer_ALE)\ **Post date:** [January 22, 2003, 10:07pm UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/15 "2003-01-22T22:07:35Z")
Does Bacterium need water to live? Couldnt they be in a host or environment that keeps them moist but not in water? Do they contain water? ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [January 23, 2003, 3:48am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/16 "2003-01-23T03:48:22Z")
> [@](#): > > \*Originally posted by Nametag \* > \*\* Water of hydration is not “chemically bound,” it’s physically bound. \*\* When I took one of the two semester chemistry courses that were required for those in my major I never understood “water of hydration.” And I still don’t. The only way I can think of for water to be “physically bound” to a molecule would be by electrostatic attraction because the water molecule is quite strongly polarized. Am I in the ball park or is there some other mechanism that our books didn’t bother to explain? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [January 23, 2003, 3:57am UTC](https://boards.straightdope.com/t/do-all-animals-require-water-to-live/150127/17 "2003-01-23T03:57:47Z")
“\>\>\>What you appear to be describing is a metabolic process in which hydrogen liberated from organic compounds combines with oxygen to form water.” In this case it is liberated hydroxide that is combined with hydrogen, but yes.