I understand that some non human animals build structures that they innately know how to build, such as how birds innately know how to build nests, and spiders innately know how to make webs, and beavers innately know how to build lodges.

Could a land animal evolve to innately know how to build a boat? If so could a land animal evolve to innately know how to make and use a sail, or a paddle to help with steering the boat?

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    $\begingroup$ Non-sentient means like a worm or spiders, right? Birds (esp Crows on New Caledonia), Dogs, bears, primates have sentience — self-awareness and emotions. They even demonstrate ‘Theory of Mind’ to a limited degree. You might get better answers if you specify an approximate critter or specify the parameters define the creature you have in mind. $\endgroup$
    – EDL
    Aug 23, 2019 at 4:04
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    $\begingroup$ Hate to be that guy but - do you mean "sentience" or "sapience"? Because almost all creatures are sentient - they are able to feel and perceive the world. "Sentience" has the same root as "sense" both in term of "I sense the smell of bacon" and "I sense hunger". Easy way to remember - sentience = can sense. "Sapience" is the capability to think and learn. So intelligent creatures would be sapient. Like Homo Sapiens. $\endgroup$
    – VLAZ
    Aug 23, 2019 at 7:18
  • $\begingroup$ Would birds (like a duck) be considered "land-based" for this question (there are a few birds that construct floating nests)? $\endgroup$ Aug 23, 2019 at 11:09

5 Answers 5


There are quite a few birds which build floating nests. Those nests are more in the nature of rafts than boats, but maybe that's enough.

  • Australasian grebes, Tachybaptus novaehollandiae.

    A pair of Australasian grebes building a floating nest
    (source: wikimedia.org)

    A pair of Australasian grebes building a floating nest. Photograph by user Grahame, available on Wikimedia under the Creative Commons Attribution-ShareAlike 3.0 license.

    Australasian grebe adult covering its egss on a floating nest

    Australasian grebe adult over its egss on a floating nest. Photograph by Keith Lightbody, available on Wikimedia under the GNU Free Documentation License, Version 1.2 or later.

  • The common tern Sterna hirundo.

    Argument between a group of common terns

    Argument between a group of common terns. Photograph by Xavier Grané Feliu, available on Wikimedia under the Creative Commons Attribution-Share Alike 3.0 Spain license.

  • Allen's gallinule, Porphyrio alleni, formerly known as the lesser gallinule.

  • Least grebe, Tachybaptus dominicus.

  • African jacana, Actophilornis africanus.

  • Ferruginous duck, Aythya nyroca.

  • And quite a few others, such as the American coot, etc.

In addition, Wikipedia says that the New Guinea crocodile, Crocodylus novaeguineae, makes floating nests to lay its eggs.

In a second addition, floating nests made of foam are not uncommon among fishes and amphibians.

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    $\begingroup$ I understand a boat – which is what the question asks for – to be a vessel for intentional directed movement. Merriam-Webster defines boat as "a small vessel for travel on water" and travelling as "going to different places instead of staying in one place". These floats have no such purpose of travelling. Their purpose is to stay safely in the middle of the water and away from the predators lying in wait in the places that a boat might travel to. $\endgroup$
    – user67090
    Aug 24, 2019 at 19:05
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    $\begingroup$ @B.L.E. In order to tease out OP's unstated assumptions and expectations, it's often necessary to make answers like this that build on one possible interpretation of a question 's imprecise wording. But even if they're not what OP is looking for, these answers are fun in a way that I think is unique to Worldbuilding SE. $\endgroup$
    – Spencer
    Aug 24, 2019 at 22:25

Yes. Fire ants make rafts.

fire ant raft


Fire ants instinctively build a raft of their own bodies to survive flood. They also instinctively make towers. The linked articles describes researchers who derived rules of behavior describing how ants, which know nothing, can instinctively behave in response to a stimulus so that these impressive emergent mass behaviors can occur. Such behaviors evolve because the emergent mass behavior is adaptive for the colony as a whole - the social insect innovation that has allowed ants to conquer the world.

Perhaps the most remarkable implication of this research is that the ants don’t have to “know” whether they are all behaving the same way. Apparently they follow the same simple rules of movement: If ants are moving above you, remain in place. If not, move randomly, and stop only if you reach an unoccupied space adjacent to at least one stationary ant.

Once the tower is built, the ants circulate through it while preserving its shape. We were surprised; we thought the ants would stop building their tower once its height was maximal. Previously, when we studied the ant raft, we were surprised in the opposite way. We thought the ants would circulate through the raft so as to take turns being underwater on the bottom. Instead, ants on the bottom can stay in place for weeks.

I do not know if the ants can pilot their rafts, but it would not surprise me. It would be the same sort of emergent behavior.
For example:

IF ant is on top of raft AND ant sees dry land, THEN ant moves towards edge of the raft nearest to dry land. The result is the whole raft generally moving towards the sighted land.

  • 1
    $\begingroup$ Add in some leaf cutter behavioural: boom. Sailboat. $\endgroup$
    – Joe Bloggs
    Aug 25, 2019 at 16:28


I'd argue that beavers, e.g., do not innately how "how to build a lodge". Rather, they innately know how to cut down trees, move them and shape them into dams, lodges, etc. I do not believe they are sentient creatures (in the usual sense of def. 2) and thus have no concept of structures and no means of communicating plans, designs, skills or novel adjustments to technique. In other words, they don't know what they're doing; they just know to do what they're doing.

I'd argue that a land animal could evolve to craft a crude boat-like-object. Something like dugout canoe could easily be made by a creature not at all unlike our happy dam building beavers. It's just a matter of applying their teeth to the job.

In order for your critters to make and use a sailboat, they'd have to innately know how to make not only a boat-like-object, but also how to make sails. This would involve innately knowing how to weave sailcloth, how to trim and stitch pieces of cloth together. It would involve innately knowing how to obtain fibres and twist rope. It would involve innately knowing how to make a mast, a boom, a keel, a rudder and various doohickies for making fast said sail. This would involve innately knowing how to make dozens of complex pieces, joining them up and using them to advantageous sailing. It would involve innately knowing at least three basic lower-level technologies that are agriculture based (jute, hemp & flax growing) plus basic higher level technologies like weaving that require other technologies (preparation of fibres, spinning threads, making looms, making sewing needles).

Most importantly of all, most of these things would require them to innately know how to make and use a language through which they can communicate all these high level technologies and coordinated actions.

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    $\begingroup$ There are ants, who can build boat-like structures out of there bodies. But in general I agree. Ability to construct complex instruments is one of defenitions of sentient creature. $\endgroup$
    – ksbes
    Aug 23, 2019 at 6:57
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    $\begingroup$ @ksbes --- Sea otters can also "build" a boatlike structure out of its body. By the simple expedient of turning over on its back! $\endgroup$
    – elemtilas
    Aug 23, 2019 at 10:41
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    $\begingroup$ This is like arguing that for an animal to build a dam they would need to be able to make concrete. Building a rudimentary sailboat doesn't require sailcloth, ropes, or complex contraptions. If I sit on a log and hold up a big leaf that qualifies as using a sail. $\endgroup$ Aug 23, 2019 at 17:22
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    $\begingroup$ @MikeNichols true, but the question is asking about sails and paddles explicitly. Look at the why behind the question: the asker clearly wants an animal that builds custom sailboats, as sophisticated as they can get. $\endgroup$
    – SRM
    Aug 24, 2019 at 1:10
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    $\begingroup$ @SRM The question asked about sails, but I feel it's obvious they didn't mean for that to imply the animals know how to make a loom or grow crops or learn a language. The examples the question gave were of animals using their own secretions or natural resources around them to construct things. Obviously, a sail doesn't have to be woven and a wind-powered vessel doesn't need ropes or masts or any manufactured components. If a question is ambiguous but one interpretation makes the question seem nonsensical and obviously impractical then clearly the other interpretation should be used. $\endgroup$ Aug 24, 2019 at 2:56

In addition to what @elemtilas has said, the development of animal skills such as nest building through evolution has to serve a purpose in the species' survival that cannot be reached more easily otherwise. For example, the nest in a tree keeps the eggs warm and safe in a way that no other behavior can in a similarly efficient manner.

So what evolutionary purpose might building a sailing boat accomplish?

It could get the animal to a place with more food or to a safe habitation accross the water.

But is developing the skill to build a sailing boat the easiest way to get accross the water to more food or a safe nest?

Certainly not. Animals that needed to cross the water evolutionarily have developed the skill to either swim or fly. In fact, almost all mammals already know how to swim (apes being the only exception). Apparently developing these abilities was easier or quicker for nature to accomplish, or we would have sailboat building non-sapient animals on Earth.

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    $\begingroup$ +1 for bringing to bear the evolutionary necessity of a behaviour (in non-sophonts)! $\endgroup$
    – elemtilas
    Aug 24, 2019 at 13:20
  • $\begingroup$ Apes are an exception for knowing how to swim? That's odd I could of sworn I knew how to swim... :P $\endgroup$
    – dsollen
    Feb 8, 2023 at 16:21

Starting with the conceit that you meant sapient instead of sentient - here's my idea. First, it depends on the physical properties of your world. This will probably only work on a planet of many small islands, separated by a greater distance than can be easily flown by most birds/flying reptiles/squirrels what-have-you.

This all starts with a small herbivore who builds nests out of small branches/logs and mud or self expressed resin. Could be beavers or bugs, doesn't particularly matter. But because of the makeup of the world - there aren't many large lakes for them to make their nests in, so they evolve to anchor their nests to rocks exposed by low tides, slightly off the coast of the islands. Maybe they build conically up from the rocks, maybe they use a biological mechanism to secure the nests so they are anchored, maybe they just build them up big enough that they stick up out of the water.

Regardless, these nests happen. I personally like to envision them as conical beaver lodges, because I like beavers.

So, these nests are built up around the islands that the creatures are native to. There are birds that can fly between islands, spreading flora and whatnot in their droppings. But not all the birds can do so. So the birds only capable of shorter flights begin to colonize the larger nests, building their nests on top of the beaver nests. This keeps them safe from carnivores, and is a benevolent sort of parasitism. Well, these birds are seed eaters. They feed from various plants and in the fullness of time, a particularly broad leafed tree gets it's seeds mixed in. The birds deposit some of those seeds while nest building on one of the island nests, and what do you know, the tree takes root. As it grows, the prevailing winds break it's bonds to the rocks - sending nest and tree off into the unknown.

The colony of beavers is stuck, the birds are stuck, and the tree is pretty obviously stuck. So the winds take this makeshift boat over time onto virgin shores, where the beavers are wildly successful, the birds are wildly successful, and the trees... well they do okay too. Eventually through self selection we develop a subrace of beavers who build weaker bonds, then eventually no bonds, because these birds are now widespread enough that their floating nests will be colonized and en-sailed. This allows new colonies to constantly form and drift around until they hit land, feast, and rebuild.


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