How Can Wild Animals Drink Water From Dirty Ponds And Lakes And Not Get Sick?

I’m sure you’d agree that ready access to clean, drinkable water is one of the biggest challenges of the modern world. The planet is home to more than 7.5 billion humans, but there still are parts of the world where a pot of clean, hygienic water is considered a prized possession. I am stressing the word ‘clean’ because water that is filled with germs or is not hygienic in other ways does more harm than good to an individual’s well being.

It’s common knowledge that unclean water is harmful to our health. Therefore, one should always take proper precautions while drinking water, especially when traveling abroad. This makes perfect sense, as waterborne diseases are some of the deadliest of all and cause millions of death around the globe every year.

However, here’s an interesting question: if drinking unclean water is so bad, how do wild animals, whose primary – or, in fact, only – source of water is rivers, ponds and lakes, which are far from hygienic, survive drinking that germ-ridden water? Why does it seem like beasts of the wild do just fine when consuming ‘bad’ water?

Well, there are a few reasons behind this, and we will take a look at some of them below.

Wild animals develop a tolerance towards ‘bad’ water

Forests are usually not teeming with water bodies. In other words, there are only a handful of lakes, ponds or other small water bodies that quench the thirst of a great deal of animals residing in the nearby wild areas. In fact, many animals come from far-off regions, braving dangers on their path, just to seek out a water source. As a result, these animals do not really have a choice to give up on one lake and casually amble over to another. They have to drink water from that very lake – their life depends on it!

Because they repeatedly drink water from the same source, or drink water with bacterial profiles that are not drastically different from each other, their bodies tend to develop a sort of resistance against such bad ‘water’. Their immune systems recognize certain bacteria due to repeated encounters with them and become more effective at dealing with them.

Animals drinking water from pond_

Repeated interactions with certain bacteria present in the water help wild animals develop an immunity towards them. (Photo Credit: Pixabay)

However, if a particular water body suddenly experiences a serious change in its profile of pathogens, it will surely lead to the death of a large number of animals who drink from it.

Not all water sources are contaminated to a dangerous level

Many people believe that water sources in the wilderness are all contaminated to a large degree, but in reality, they’re not that bad. I mean, they may be contaminated to a certain degree, but they are not so full of germs that it will definitely cause a problem for anyone drinking it, be it animals or even humans.

Furthermore, most mammals have a finely developed sense of smell, which helps them ascertain (to a certain degree) if a water body is bacteriologically active. If they encounter such a body, many times they simply pass on the idea of drinking from them.

small pond in jungle

Not all water bodies are contaminated enough to kill you. (Photo Credit :

Not all bacterial illnesses are necessarily fatal

As it turns out, many illnesses caused by bacteria present in water bodies are simple bacterial infections. In that sense, they’re more of an inconvenience than an actual threat to the lives of anyone who drinks from these water bodies.

Evolution plays a role

The animals that survive after drinking water from ‘dirty’ ponds will reproduce, and in the process, pass on their ‘highly-tolerant-against-water-germs’ genes to their offspring, who then become inoculated (sort of) against a specific profile of microorganisms found in water.

(Photo Credit : Flickr)

This might be an oversimplification of the underlying process of evolution, but in a nutshell, it simply means that if there’s a scarcity of water sources, then the animals that are able to drink water from the dirtiest puddles without major consequences have an advantage over those that fall ill or die.

Animals that drink water from dirty ponds die all the time

After reading through all the points mentioned above, you may believe that animals do a pretty job at digesting even the dirtiest of water, and that drinking unclean water isn’t that big of a deal in reality.

If you have that idea, then let me tell you something…

The truth is that animals get sick and die all the time from drinking bad water. We only see them drinking water from such dirty ponds and assume that they digest all that contaminated stuff like champs. However, we don’t see it when they hide somewhere (under the bushes or in the undergrowth), puke their souls out and die prematurely due to infections they contracted from the water they drank from a particularly dirty pond.

Many animals have the tendency to hide when they’re dangerously ill, and stay in hiding until they either recover or die. Therefore, you normally don’t see the animals that have gotten sick from drinking water from dirty sources. This sort of hiding behavior in animals is referred to as terminal burrowing. Even humans have been found to exhibit this in cases of gradual hypothermia (Source).

In a nutshell, while it’s true that not all water bodies in the wild are contaminated so badly that even a sip of water from them will kill anything that drinks from them, that doesn’t mean it’s inherently okay to drink contaminated water and assume that one’s immune system will protect them, regardless of how bad the water is.


  1. National Center for Biotechnology Information (NCBI) Research 1
  2. National Center for Biotechnology Information (NCBI) Research 2
  3. Stanford University School of Medicine
  4. Penn State Extension
  5. University of Florida’s Institute of Food and Agricultural Sciences
  6. University of Georgia
  7. Idaho State University
  8. North Carolina State University
  9. Michigan State University
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Ashish is a Science graduate (Bachelor of Science) from Punjabi University (India). He spends a lot of time watching movies, and an awful lot more time discussing them. He likes Harry Potter and the Avengers, and obsesses over how thoroughly Science dictates every aspect of life… in this universe, at least.

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