“Who” vs. “Which” for Animals


Use who instead of which for animals with names.

  • Here is a picture of my cat Hobbes, who/which has the cutest black nose.
  • My roommate’s cat, who/which is as large as a small dog, loves being carried around like a kitten.

Who may indicate emotional closeness or be used for an animal that is personified (even one without a name).

  • Meanwhile the cat, who had found the butter, was pretending that butter-coated whiskers had been the idea all along.
  • The big black dog who followed us home had the most soulful eyes of any creature I’ve seen.

Also use who for anthropomorphized animals in creative writing. The following sentence is from a novel in which the animal characters are given human characteristics.

  • So did the geese, who lived with the sheep.
    E.B. White, Charlotte’s Web (1952)

But to discuss a species in general or an unknown animal without a name, use which or that instead of who.

  • The Barbary lion is among the many populations of lion who/that have gone extinct in the wild.
  • The kakapo, who/which has the face of an owl and the walk of a duck, is the only flightless parrot in the world.
  • The video shows a man approaching the moose, who/which then charges at him.

Note that who may be used to discuss animal behavior in scientific and academic writing.

  • By contrast, the highly social mongooses, who live in ‘mobs’ with an average size of nearly 30, were among the worst performers.
    — David Z. Hambrick, “What Hyenas Can Tell Us about the Origins of Intelligence,” Scientific American (May 30, 2017)

Who, which, that as relative pronouns

The pronoun who is used in relative clauses, generally to describe people.

  • My friend Maya, who loves to travel, has discovered a hidden island.
  • People who look for the best in others often find it.
  • I once knew a woman who could fly.
  • Applicants who have already registered need not register again.

The pronouns which and that also function as relative pronouns. They usually refer to things (although that can also be used for people).

  • This new app, which tracks your activity levels, also tracks you.
  • The postcard that came this morning is from my friend in Thailand.
  • People that like cheese love pizza.

All three of these pronouns—who, that, and which—can be used for animals. In this article, we discuss when to use which relative pronoun to refer to animals.

Who vs. which or that for animals

Use who instead of which or that for animals with names. But to refer to a species or to animals without proper names, use which or that instead.

  • Rita goes swimming with her dog Lava, who/which loves the ocean.
  • My cat Tooks, who/which is quite talkative, keeps me up at night with her chatter.
  • Hobbes, who/which goes quite bravely to see the vet, is terrified of birds.
  • but
  • A wolf pack comprises wolves who/that have a defined territory.
  • The Hawksbill turtle, who/which has a beak-like mouth, is now a critically endangered species.

Use who for an animal if the relationship is familiar or personal (e.g., a person’s pet or companion) even if the animal’s name is not mentioned in the sentence. In other words, if an animal is personified, refer to it as you would to a person.

  • My neighbor’s cat, who loves to play, often visits me in the afternoon.
  • Don’t unnecessarily interact with a guide dog who is working.
  • I think I’ll go look at pictures of dogs who don’t understand how big they are.
  • There are cats who like being groomed, and cats who don’t.

Thus, whether someone uses who or which to refer to an animal can indicate their level of emotional closeness to it.

  • This little dog, who/which seems to be lost, has followed me home.
    The speaker might use who instead of which if they have already developed an attachment to the lost little dog.

Animals may be anthropomorphized in creative writing, be given human traits and characteristics. The writer will then use who instead of which (and he or she instead of it) for these animals.

  • He has gone to see his friend Pooh Bear, who is a great friend of his.
    A.A. Milne, Winne-the-Pooh (1926)

In scientific and academic writing, who may be used instead of which or that to discuss animal behavior. Who is also used for animal subjects with names.

  • Male bonobos who have their mothers present in the community usually establish strong social ties.
    — Girard-Buttoz et al., “Variable Use of Polyadic Grooming and Its Effect on Access to Social Partners in Wild Chimpanzees and Bonobos,” Animal Behaviour (Vol. 68, Oct. 2020)
  • She [a chimpanzee mother] had become too tired to cope with the aggressive demands and tantrums of Flint, who wanted to ride on her back and sleep with her even after the birth of his new sister.
    — “The ‘F’ Family,” Website of the Jane Goodall Institute Australia (Accessed July 29, 2022)

That can always replace who in restrictive clauses (which are clauses that are essential to meaning), even to refer to people.

  • Students who/that need help can send me an email.
  • Cats who/that like cheese love pizza.

In formal usage, who is preferred for people and that for animals. However, when discussing animal behavior (an animal’s preferences or choices), using who over that is acceptable.

Additional guidance

Grammar and style authorities generally agree that who should be used for animals with names. Merriam-Webster, in its dictionary entry on who, states that this pronoun can refer to animals. The AP Stylebook agrees, specifying that who instead of which is used for animals with names. The Chicago Manual of Style does not provide specific guidance on using who for animals, noting only that who “normally” refers to humans.

The APA Publication Manual recommends using who for people and that or which for animals in general. However, it then suggests he and she be used instead of it for animals with names, which would allow for the use of who instead of which for such animals.


Use masculine and feminine pronouns like he/she and her/him instead of it for pets and other animals that have names and whose sex is known.

  • My cat Tooks thinks everything I do is for it/her.
  • Bessie the cow likes to have its/her tail brushed.

Examples from published content

Here are some examples from published writing that show how who can be used for pet and other animals that are personally known or are named.

  • It took all her resolution not to cry when she bade farewell to [her cat] Mike, who was curled up on the sun-warm grass at the back door.
    Lucy Maud Montgomery, Emily of New Moon (1923)
  • The cat, who had been pacing continuously, took one look and leaped into Phil’s arms.
    — Katherine Schulz, “Why Animals Don’t Get Lost,” New Yorker (Apr. 5, 2021)
  • All the dogs who come into Llandeilo primary school have been trained for what can be a stressful and noisy environment.
    — “Llandeilo Primary School Uses Pets to Help Pupils,” BBC News (June 23, 2022)
  • Queenie, a cow who escaped from a slaughterhouse in Queens in 2000, is here. So is Simon, a goat who was abandoned after growing up in a Brooklyn apartment.
    — “Where the Cows Come Home; Sanctuary Farm Applauds Ban on Butchering of Sick Animals,” New York Times (Jan. 2, 2004)

When animal behavior is discussed, who may be used instead of which or that, as seen in these examples.

  • Male chimpanzees, who remain in the community in which they were born through adulthood, come to know their mother’s core area from a young age.
    — Maureen McCarthy, “Chimps in Uganda: Home Sweet Home,” Scientific American (Oct. 1, 2012)
  • Cats who completely rejected the food were excluded from the analysis.
    — Cechetti et al., “Provision of High Meat Content Food and Object Play Reduce Predation of Wild Animals by Domestic Cats Felis catus,” Current Biology (Vol. 31, Issue 5, Mar. 2021)

Anthropomorphized animal characters in creative writing are referred to using who rather than which or that (and he or she instead of it).

  • ‘Ah, that’s bad,’ said Mr. Beaver shaking his head. ‘That’s a very, very bad business. There’s no doubt he was taken off by the police. I got that from a bird who saw it done.’
    C.S. Lewis, The Lion, the Witch, and the Wardrobe (1950)
  • All that year the animals . . . were happy in their work; they grudged no effort or sacrifice, well aware that everything they did was for the benefit of themselves and those of their kind who would come after them, and not for a pack of idle, thieving human beings.
    George Orwell, Animal Farm (1945)
  • The poor little Lizard, Bill, was in the middle, being held up by two guinea-pigs, who were giving it something out of a bottle.
    Lewis Caroll, Alice’s Adventures in Wonderland (1865)

Usage guide

Use who instead of which for people’s pets and other animals with names. Also use who for animals that are personified or anthropomorphized. To discuss an animal species or to refer to unknown animals, use which or that. However, when animal behavior is discussed (such as habits and preferences), who may be used instead.

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Did You Know?

The plural of a name ending in y is formed by simply adding s (the Murphys, not Murphies).
Know more:Plurals of Names Ending in “Y”