What do animals eat? (And how does this relate to an optimal human diet?)


Hi all,
A thought came to me out of the blue the other day, and after reflecting and researching it a bit I was quite surprised by the answer. After about 10 years of interest in health and nutrition I can’t remember any reading, listening to or watching anything about the subject (I am sure it’s been covered but it can’t be that common a concept otherwise I would definitely have come across it). Anyway it led me to this little thought experiment which I thought I would share with you. I’ve gamified it a bit so maybe it’s something you could even try with your family if you wanted. It’s quite simple and there’s no trick questions or anything and you’re free to use the internet or books, it’s not a test of your brain power!
I hope it will be a springboard for a bit of a discussion with you enlightened people and I look forward to reading the responses.

So here we go.
Name 3 animals that eat the following foods:

  1. Other animals (eg meat, seafood, reptiles, eggs, insects)
  2. Grasses (and related plants)
  3. Leaves (trees & bushes), shoots, trees
  4. Nuts and seeds
  5. Fungi
  6. Berries (eg blueberries, raspberries, strawberries etc)
  7. Fruit (eg apples, bananas, oranges, mangoes etc)
  8. Vegetables (eg carrots, potatoes, tomatoes, cucumber, lettuce, cabbage, cauliflower, beans, lentils etc etc)
  9. Dairy
  10. Honey

Scoring System:
3 points: Animals that eat the food as the majority of their diet (80% and over)
2 points: Animals that eat the food as a large part of their diet (40% or so)
1 point: Animals that eat the food as a small part of their diet (10% or so)
Score for each category then total up at the end.
Maximum score: 90 points
For clarification: Only wild animals in their natural habitat count - not pets, farm animals or zoos! And we are only considering what animals prefer to eat for optimal health in their natural environment (not what they eat just to survive in times of famine etc).

Here’s my answers:

  1. Other animals (eg meat, seafood, reptiles, eggs, insects)
    Lion -3, anteater -3, shark -3 = 9 points (easy)
  2. Grasses (and related plants)
    Cow -3, sheep -3, horse -3 = 9 points (easy)
  3. Leaves, shoots, trees
    Panda -3, elephant -3, beaver -3 = 9 points (OK but a bit more difficult)
  4. Nuts and seeds
    Squirrels -2, birds -2, mice -1 = 5 points (a lot more difficult than I expected)
  5. Fungi
    Wild pig/boar -1, deer -1, bears -1 = 3 points (very difficult as expected)
  6. Berries
    Turkeys -1, foxes -1, bats -1 = 3 points (a lot more difficult than I expected)
  7. Fruit
    Fruit bats -3, monkeys -2, bears -1 = 6 points (a lot more difficult thanI expected)
  8. Vegetables
    Rabbits -1, wild pig / boar -1, mice -1 = 3 points (really difficult, absolutely the opposite of what expected)
  9. Dairy
    As adults -0 = 0 points (as expected)
  10. Honey
    Bears -1, racoons -1, martens -1 = 3 points (a little bit more difficult than I expected)

My score: 50 points
Maximum: 90 points

I tried to vary the animals in my list to make it a bit more interesting. My score could probably be beaten by a few points by choosing specific animals eg choosing specific species of bird or mice etc.
I look forward to seeing what the top score will be. Good luck everyone.


interesting in that one can only do this in a ‘perfect’ eating situation.

I mean any physical living thing WILL EAT anything for survival. It will eat whatever at all times just for that survival whether that will help it or not right?

so in a perfect world, but nature is not perfect ever. Humans manipulate all of it truly now.

I saw an animal rescue show where a dog left abandoned was eating the chestnuts that fell from a tree where it was chained cause it had to eat something and it was sad as heck of course but that dog ate nuts for survival. Ate full shelled nuts and crapped out full shelled nuts too…ugh

fruit bats love mainly fruit but will eat insects too and I see SO many animals and put us there to as humans, that will eat what all nature will allow at all times for total survival.

Like Koalas who are specialized to process Eucalyptus leaves to their best advantage can survive on other leaves if needed, but they will never be their best food and not be best for their top health.

Any animal, human too will eat anything for total survival whether it is in any good or not for their system, after all we die fastest with no air, then water, food is that last fail safe in which any living thing can try to survive.

Thank the heavens life gave us options for survival regarding food intake. Almost everything on the planet can do plant and animal foods for survival to some extent. Most if not all living things have a back up truly for survival on food until ya run out of options and perish.

OK I am sorry I went off track. I get that the planet has a natural system to it but one blip in that natural chain or thru human manipulation it goes so off what where nature and survival is concerned.

so for your list, every animal and human will try to eat every darn category that is listed :slight_smile: that is how I see it. I might be way off track on my post :crazy_face::partying_face:


Hi thanks for being the first to respond. You raise some interesting points regarding eating to survive.
What I want to get at with this thought experiment / game however is what is good and bad for human health via examining what animals eat.
So really I want to see what animals prefer to eat for optimal health not just survival.
(Although what happens to animal health when they are forced to different food just to survive is a very interesting thought for another time!)


cool. I feel ya on that. I think every animal truly thru ‘studies and observation’ of all critters on this planet is listed somewhere cause us humans have done that research for sure.

Lions tigers and bears, oh my
Cattle, lamb, horses
koala, gorilla, goats
birds, squirrels, deer
bears, birds, butterflies
bats, bears, monkeys
rabbits, horses, cows
DAIRY…baby animals only. there is no ‘wild out in nature’ dairy other than that LOL
bees make it, do they ‘eat it’? lol. bears, humans

ok I hit the list a bit, SO many options I chose those


I think thats a pretty good list.
Bees do eat their own honey - thats what its for!
However are you sure that rabbits, horses and cows eat vegetables? If so what percentage of their diet?


I am half-awake (shopping is so very much tiring when one does a big one once per month…), just a few thoughts.

What is a vegetable? isn’t that a kitchen term only that humans use? I don’t know any wild plant that is vegetable but maybe English works differently and I don’t know these things… That’s quite possible.

And what is berries? Banana is a berry while blackberry isn’t if we consider the word properly but humans use it strangely… Whatever, they are way too close to “fruits” to me. If an animal eat one, they probably eat the other group too?

And even for survival, not all animals eat anything. A rabbit would have serious problems with either honey or fat… Omnivores have it way easier. But humans are omnivores and we still die from certain fungi other animals eat happily. And we may eat grass of wood but we can’t get much energy from it unlike many other species…

I don’t give a list, mine is very close to what Fangs wrote (I went with goats though :smiley: wonderful animals. and I started with snakes, they are very seriously carnivores, I doubt anyone could catch one eating plants or fungi :D) except I just stopped thinking about it around berries… Fruit bats and many monkeys eat plenty of fruits, I know that much :wink: Honey is dense so probably many animals gladly eat some, I saw videos about non-avian dinosaurs too… Bears and humans are the most famous honey eaters though and bees so it’s the same as Fangs’s answer, again.

Some species are very much opportunistic with very varied diets even without some super serious force going on. Mice, rats, humans are like that. And deep sea animals truly eat whatever they can, they have a serious force all the time, survival isn’t trivial there! A whale-fall helps a lot though.


farmer all my life. raised rabbits, horses and cattle.
we had crops and nothing was ever wasted, when no use, feed to livestock and it was devoured LOL Mr McGregors garden was ravaged by a bunny but horses and cattle, yea not so much ‘free eats’ from a veg garden or acres of crops unless a fence break, lol, I would guess. Lower percent on them.

I also thought drones never ate their honey, just for queen and the offspring…now I gotta go check the internet on that HA

Ahhh from the 'net:
Yes , some species of bees make and eat their own honey. But with that in mind: Most bees’ main diet consists of pollen and nectar from flowers. Pollen is their protein source, and nectar is their carbohydrate source. But certain bees, like honeybees, supplement their diet with honey when nectar sources are low.

so what is their own honey percentage eaten? hmmm…thinking lower but winter more of a survival food for them?


Hi Shinita,
Thanks for playing! A couple of points in reply to your answer:
For this thought experiment as definitions of fruits and vegetables and berries, Im just thinking of how they would be classified in your local supermarket. Nice and easy, no need to go into to deeply for this exercise.
So, do the same animals eat fruits and berries? From what Ive seen so far in my limited research Im not sure many of them do (although like like you I would also have thought so before I looked it up!)
As for honey I like you assumed honey would be a prized food in the animal kingdom, but as far as I can see its actually pretty limited - maybe only 10 or 15 species.
And no answer to one of the most important questions - which animals eat vegetables?
A good point about sea creatures - as far as I know most are carnivores, some are omnivores and very few are herbivores. Im a diving instructor and had never really considered it before.
Let me know if you come up with an answer to the vegetables question!


Thanks again for the reply and the interesting info about bees. Im with you on the honey being a winter survival food, thats what I thought. My girlfriends dad is a beekeeper so Ill check up with him too.
Remember for this experiment that were only talking wild animals in natural habitat for this thought experiment - so pets, farm animals and zoos are not counted as that involves human interference in the animals diet.
Interesting point about the rabbit as that was one of the only animal I could come up with in my vegetables answer, then I found this:

Even though they feed on various vegetation, wild rabbits are very picky eaters when it comes to what goes into their bellies. They prefer fresh foliage (leaves and plants collectively) to dry plants. A large number of wild rabbits are known to climb trees to access fresh leaves and vegetation. They enjoy feeding on delicate plants.

In warmer seasons, rabbits will eat:

  • Grasses –contain various nutrients, vitamins, and fiber that aid in the digestion of food.
  • Flowers and wildflowers –such as jasmine, willows, and roses are enjoyed by wild rabbits.
  • Clovers – the whole plant is consumed, including the stem, leaves, and flowers.
  • Weeds – such as buttercups, daisies, and dandelions are included in wild rabbits diets.
  • Vegetable plants –examples include kales, spinach, and raspberry leaves.
  • Tree seedlings –like broccoli, beans, and lettuce are eaten by bunnies.

In drier seasons, wild rabbits will indulge in foods like:

  • Twigs –wild rabbits mostly gnaw on them to regulate the size of their teeth.
  • Tree bark –rabbits will consume the soft parts and even twigs to aid in digestion.
  • Pine needles –ordinary pine needles are not harmful to rabbits though they are spiky and sharp.
  • Buds
  • Dry and green grasses
  • Leafy weeds
  • Shrubs

So maybe rabbits do sometimes eat vegetables but it doesnt seem like one of their main food sources. The answer here only states leafy green vegetables, which fits in with their diet of leaves I suppose.
So maybe we can give that answer 1 point on our scoring system.
So we have three people playing so far and no answer to the question what animals eat vegetables? Strange eh?


Sorry I forgot to reply to one of your points that is actually quite crucial to the game as its one the subjects Ive been thinking about recently which lead in part to this little thought experiment. You state that humans are omnivores and Ive always thought that too, but Im starting to wonder if thats true. To me an omnivore should thrive on all the foods it eats not just survive. Im not sure thats true for humans. If we eat just meat the carnivore community seem to have proved they thrive. Vegetarians would be lacking certain nutrients esp B12 if supplements didnt exist so i think survive rather than thrive in the long term, vegans even more so and a fruit only diet can be deadly after a few years.

(Geoffrey) #11

Deer. They will get the majority of their nutrients from plant matter of all sorts. Probably 90-99% but I have seen them eat animal protein in the form or birds, snakes and internal organs of other deer.

Bears. They will eat just about anything that is available to them.

Coyotes, Whole they are predominantly meat eaters they are also opportunistic and will not pass up an opportunity to eat some plant matter is hungry.


Hi Geoffrey,
Thanks for playing!
In reverse order:
Coyotes - seems like one of the few animals that do eat some vegetables. However just a very small amount. So a 1 on our scoring system.

According to Coachella Valley Preserve, 90% of a coyote’s diet is meat. The rest of their diet comprises insects, fungi, fruits, and vegetables.

Bears - it seems eat almost all the categories except diary and vegetables.

Really interesting about the deer, I had no idea their diet was so varied - true omnivores. However, I did find this very interesting article about what deers should not eat and it seems many vegetables are toxic to them.

Some of the food substances you should avoid feeding deers include:

  • Potatoes –are deer-resistant plants, and therefore deer will avoid eating them.
  • Kitchen scraps –These are carrot pulp, fruit peeling, or herb stems. Deer lack the bacteria required to digest these foods. They will die of hunger.
  • Hay –during winter, deers are in browsing mode; hence they lack the correct bacteria in their digestive tracts to digest hay. Ultimately, this will lead them to die of starvation regardless of feeding on the hay.
  • Grapes and raisins –have high sugar contents that may prove harmful to deer during the winter season.
  • Wild mushrooms –are poisonous to deer and may be deadly to the animals if ingested.
  • Corn –due to its capability to ferment quickly, corn may cause problems to the digestive system of deers.
  • Tomatoes –are part of the nightshade family, many of which can be poisonous to deer.
  • Tomato leaves- apart from the fruits, the fruit of the tomato plants are also toxic to these hoofed animals.
  • Rhubarbs –These plants are a part of the nightshade family. They contain oxalic acids. When ingested in large amounts, they cause gastrointestinal problems, kidney stones, and even kidney failure.
  • Eggplants –are a part of the nightshade family, which are toxic to deer and other ruminants.
  • Cucumbers –may seem healthy but are also among the nightshade family that harms deers.
  • Rosemary –contains volatile oils, which cause stomach upsets and even depression in these ruminants.
  • Onions –are members of the allium family, which results in complications such as anemia to deers.
  • Chives – are part of the allium family. They cause the blood cells of the ruminants to rapture, in the long run, leading to anaemia,
  • Carrots –are edible, yes, but only the tip and the stem. Roots of carrots can prove harmful if eaten.
  • Garlic –causes anaemia in deers of all species.


So a quick summary of how we are doing so far. For the first 7 food categories we have animals that eat that food at least as part of their natural diet. However the categories so far that we are really struggling with are the last 3 - vegetables, dairy and honey. This so far tallies with my original out of the blue thought. I really expected my hypothesis to be overturned rather than confirmed. Lets see what others can come up with.

(Geoffrey) #14

I listed those particular animals because I hunt them and have observed them eating the things I’ve listed.

(KM) #15

All juvenile mammals “eat dairy”; they drink milk. That is what the word mammal means. Animals who are not mammals do not drink milk, outside mother’s bodies “dairy” does not appear in nature.

I’m also not understanding the definition of a vegetable - isn’t it any part of a plant other than the fruit plus a few rarities like bark and pollen and flowers?


Hi Geoffrey, I guessed from the animals you picked that you might be a hunter. What Im trying to tease out from people’s answers is to see what animals eat for an optimal diet and thereby see what may or may not be healthy for humans to eat, especially related to vegetables and diary.
As a hunter you must observe many animals - have you seen any that would describe as eating vegetables (probably root vegetables in that environment), fungi or dairy (milk) as adults? If so what percentage would think it makes of their diet. Im having trouble coming up with any any animals that would score more than a 1 in these categories. Thanks for you input.


Hi kib1, thanks for playing! Interesting comment about the milk and mammals. Thats exactly what I was thinking. Milk is obviously really healthy for mammals as that’s how they grow their young. If milk is such a food healthy for mammals then why does that feeding stop at a certain point? Is that because at a certain milk becomes bad for them or is it more because its bad for the mothers health to lactate for too long? In that case is it bad for cows to keep producing milk long term? Maybe some farmers can answer that one? And the next question, is it bad for young animals to be fed milk from another animal? This obviously wouldn’t happen in nature but maybe a rescued wild animal whose mother had died. Maybe vets or farmers would know?

About the vegetables definition - what I am eventually trying to get at with this thought experiment / game is what is good and bad for human health via examining what animals eat eg if animals don’t really eat vegetables should we?
So for this thought experiment as definitions of fruits and vegetables and berries, Im just thinking of how they would be classified in your local supermarket. Nice and easy, no need to go into to deeply for this exercise.

(Doug) #18

Animals --> Turtles --> Mutant Ninja variety --> Teenage years --> they eat pizza.

(Jane) #19

Nobody has mentioned chickens or turkeys yet, but in the wild they would eat insects and grasses.

(Edith) #20

Even sheep have been known to diversify their diets when necessary.

An interesting podcast with a man named Fred Provenza, discusses how animals (in his case he does study farm animals, mostly goats if I recall) will eat what they need, even sometimes plants that help them medicinally. They also will naturally not eat too much of the same thing.


It could be that there is no animal that is an absolute herbivore.