Why the question is harder than it sounds
The trouble starts with the word "language." If language means any system for sharing information, then many animals qualify: they signal alarm, advertise themselves, and coordinate with group members. If language means the specific human package of words, grammar, and flexible meaning, the answer changes. One review argues that communication covers a much broader range of meanings than people usually assume, and that no other species has a communicative system with any substantive resemblance to human language [1].
A second problem is the yardstick. A 1990 review of animal language capacities noted that how you set the comparison matters enormously: if you begin by expecting to find no language-like skills in animals, you will design and read studies very differently than if you begin from the opposite assumption [2]. In other words, the question "do animals have language?" is partly a question about what we are willing to count.
Animals show pieces of language, not the whole thing
The most striking pattern is that proposed hallmarks of human language keep turning up in animals in weaker form. A 2023 analysis describes how, each time scholars name a property that sets human language apart, such as reference or syntax, some attenuated version of that property is later found in animal communication [4]. That is real evidence of overlap, but it is overlap in fragments rather than a full linguistic system.
The same analysis argues that the uniqueness argument has recently moved from linguistic rules to the mental machinery underneath them. The current claim is that human language rests on ostension and inference, roughly the ability to point someone's attention at something and to draw conclusions about what they mean, while animal communication is said to depend on simple associations and largely hardwired signals [4]. Notably, the paper says these characterizations are often borne out in the published data, so the difference is not being dismissed as an illusion.
The measuring tool may be hiding what animals do
Here is the twist. The same 2023 analysis argues that the apparent gap is partly manufactured by method. The field of animal communication has been shaped by what is called the "code model," which imagines communication as information packets that are encoded, transmitted, decoded, and interpreted [4]. That framework made it easy to standardize studies of meaning in animal signals, but it leaves little room for the nuance, ambiguity, and context-dependent variation that human language shows. The paper calls the code model "insidious" because it is rarely named directly yet strongly shapes how animals are studied [4].
The implication is that some of the difference between animal and human communication may be a difference in how the two are observed. The paper suggests that if researchers adopt approaches that stop searching for codes, animal communication and human language may turn out to differ in degree rather than in kind [4]. That is a proposal about future work, not a demonstrated result, and it sits in tension with the stronger claim that no species resembles human language at all [1].
The idea that animals speak is old, and not only scientific
Belief that animals possess language has deep cultural roots that predate modern research. A study of Islamic saint cults in Azerbaijan, the Caucasus, Anatolia, Iraq, and Central Asia describes how ancient hunters totemized animals and came to believe they had a language like humans, with knowledge of animal language treated as a gift from God [5]. Over time, as polytheistic religions gave way to monotheism, the role of the serpent as a mediator passed to prophets, imams, saints, and Sayyids, who were said to talk with animals, heal their wounds, and protect them from hunters [5].
This matters for the scientific question only as context. It shows that the intuition that animals have language is not a naive modern mistake but a long-standing cultural archetype, which may help explain why the debate keeps returning to the same question. The research evidence itself, however, does not support the claim that animals possess a language comparable to ours [1].
Sources used in this answer
Animals do not communicate like humans do, nor have they language
The paper argues that communication has a broader range of meanings than usually acknowledged and that no other species possesses a communicative system with substantive resemblance to human language.
Language capacities of nonhuman animals
The paper reviews language capacities in nonhuman animals and stresses that the choice of comparison standard is critical to interpreting studies of animal language.
The language of animals
The paper examines animal communication in relation to human language and considers whether any original animal languages can be established.
Overcoming bias in the comparison of human language and animal communication
The paper argues that differences between animal communication and human language are partly driven by the different theoretical models used to study them, and that the two may differ in degree rather than kind.
Belief in the knowledge of animal language in the context of the cult of Islamic saints
The paper describes beliefs in animal language within Islamic saint cults, tracing how ancient hunters' attribution of language to animals evolved into a religious and cultural archetype.