system
Given the following post, respond as if you're commenting on Reddit:
human
Can animals reason and use language?
gpt
There are *many* different kinds of animals. Also, we don't know a great deal about how nonhuman animals think, so direct answers to your question (even regarding particular species) are all partly conjecture for the time being.

Some animals, such as earthworms, apparently have no reasoning capacity (they operate unthinkingly, entirely on reflex) and no language to speak of.

Some animals, such as hive insects, have no reasoning capacity but *do* engage in certain kinds of communication which might be called 'language'. Notably, bees have a 'dance' wherein they indicate with the motion of their bodies which direction to go from the hive in order to find food. However, these communication schemes are *not* a social development like human languages are, but rather built into the animals' biology; they cannot possibly learn a new 'language'.

Note that, in general, *all* invertebrates seem to be incapable of reasoning, save for the cephalopods and *possibly* portia spiders. On the other hand, most vertebrates seem to possess reasoning capacity, with mammals (save possibly the naked mole rat) and birds in general being the clearest examples.

Some animals have reasoning capacity but no language to speak of. This category probably includes many kinds of fish, most octopuses, and some amphibians and reptiles.

Some animals have reasoning capacity and 'language'. The obvious example is birds that sing to each other. Many birds and mammals fall into this category, along with probably some amphibians, reptiles, fish, and squid. However, in most of these cases it appears that the communication schemes are built into the animals' biology and they possess little or no ability to learn any expansion on their language.

Besides humans, there are some other examples of animals which apparently *can* learn entirely new features of language. There has been some success in teaching sign language to other apes, such as chimpanzees and gorillas. Also, research suggests that cetaceans (that is, whales and dolphins) possess 'dialects' and learn different ways of 'speaking' from each other. Some other animals, such as dogs, horses and parrots, can be taught to respond in unique, non-instinctive ways to human voice or sign commands (e.g. a dog sitting down when you say 'sit'). However, other than the apes and cetaceans, this learned 'language' seems to be a fairly one-way thing; that is to say, the animals respond to *humans* saying things but show little or no indication of using that same 'language' with *each other.*

The one language feature that all nonhuman animals seem to lack is *grammar.* While apes can be taught 1-to-1 associations between specific signs and specific meanings, they don't seem to understand that the signs should be sequenced in a particular way relative to each other. For instance, where a human who wants a banana will always sign 'I want a banana' (grammatically correct), the apes are just as likely to sign 'want banana want banana me' or 'banana me want me banana banana' or any other jumble of signs with those meanings all mashed together. They know that they're putting those meanings together with each other, but the idea of an *abstract rule* by which arbitrary meanings within certain categories (noun/verb/adjective, subject/object, etc) can be systematically assembled into phrases seems to entirely escape their understanding. If you're using a narrow definition of 'language' that requires structured grammar, in that case humans seem to be unique on Earth in our ability to understand and use that kind of language.