Hockett's design features

[citation needed] Hockett later added prevarication, reflexiveness, and learnability to the list as uniquely human characteristics.

When Hockett first defined this feature, it did not take sign language into account, which reflects the ideology of orality that was prevalent during the time.

In contrast, other forms of communication such as writing and Inka khipus (knot-tying) are more permanent.

In spoken languages, iconicity takes the form of onomatopoeia (e.g., "murmur" in English, "māo" [cat] in Mandarin).

For the vast majority of other symbols, there is no intrinsic or logical connection between a sound form (signal) and what it refers to.

Thus, while Hockett did not account for the possibility of non-arbitrary form-meaning relationships, the principle still generally applies.

Linguistic representations can be broken down into small discrete units which combine with each other in rule-governed ways.

The plural morpheme is perceived categorically, not continuously: one cannot express smaller or larger quantities by varying how loudly one pronounces the /s/.

Displacement refers to the idea that humans can talk about things that are not physically present or that do not even exist.

Also related to productivity is the concept of grammatical patterning, which facilitates the use and comprehension of language.

New idioms are created all the time and the meaning of signals can vary depending on the context and situation.

Also a very defining feature of human language, reflexiveness is a trait not shared by animal communication.

Some animal communication systems are impressively sophisticated in the sense that they possess a significant number of the design features as proposed by Hockett.

Ants produce chemicals called pheromones, which are released through body glands and received by the tips of the antenna.

Ants can produce up to twenty different pheromone scents, each a unique signal used to communicate things such as the location of food and danger, or even the need to defend or relocate the colony.

The queen ant has special pheromones which she uses to signal her status, orchestrate work, and let the colony know when they need to raise princesses or drones.

[5] Bird communication demonstrates many of the features: the vocal-auditory channel, broadcast transmission/directional reception, rapid fading, semanticity, and arbitrariness.

Songs are used primarily to attract mates, while calls are used to alert conspecifics of food and danger and coordinate movement with the flock.

[8] Two different bird species, the Southern Pied Blabber and the Japanese Tit have been observed to be using the duality of patterning, which is another feature thought to only be used by humans.

Their communication is also not arbitrary: They move in a direction and pattern that physically points out where food is located.

Honeybee dancing demonstrates displacement, which is generally considered a human characteristic.