Do Cats Know Their Littermates? The Surprising Bond Between Feline Siblings


Cats form social bonds and relationships just like humans do. One of the most important bonds for a cat early in life is with its littermates. But what happens when kittens are separated at an early age? Do they still recognize their siblings later in life?

This is an interesting scientific question about cat behavior and social bonds. Research has shown that cats use scent, sight, and sound to recognize their siblings, even after long separations. The memory of littermates and familial bonds can persist into adulthood, despite cats dispersing to new homes at an early age. In this article, we’ll explore the evidence on whether cat siblings know and remember each other.

Scent and Familiarity

Cats develop bonds and familiarity with siblings from a very young age that are retained even after separation. One of the main ways cats recognize their siblings is through scent. A cat’s sense of smell is highly advanced compared to humans. According to a study by, a cat’s nose has nearly 200 million olfactory receptors, while humans only have about 5 million. This gives cats an extremely powerful ability to detect and remember scents.

Cat siblings who grow up together have prolonged exposure to each other’s scent from kittens through adolescence. Even if separated, they retain memories of their littermates’ smells. When reunited later in life, cats often recognize the familiar scents of their siblings. Scent provides a key sensory and neurological link to early bonds formed between kittens. While vision and hearing fade, cats can recognize kinship through enduring scent memories.

Experiments with Separated Litters

There have been some interesting studies looking at kitten behavior when siblings are separated and later reunited. One study published in PLoS One separated kittens from the same litter at 7 weeks old and housed them individually for 5 weeks before reuniting them (Lowell et al., 2020). When the kittens were reunited at 12 weeks old, researchers observed their interactions and behaviors. The kittens displayed social behaviors like sniffing, following, and playing with their siblings, suggesting they recognized each other after the 5 week separation. Another study published in Applied Animal Behaviour Science found that even after a 20 week separation from litter mates starting at 3-4 weeks old, most kittens still recognized and interacted affiliatively with their siblings when reunited (Caugului et al., 2014). These studies demonstrate that despite early separation, kittens are still able to identify their siblings through social interactions weeks or months later.

Brain Development Factors

Research shows that early brain development leads to long-term memories of siblings in both humans and other mammals. Rodent pups, for example, develop a preference for their own mother’s scent within a week after birth. This allows them to identify and locate their mother and littermates (Rogers et al., 2018).

In humans, the hippocampus and prefrontal cortex regions of the brain are critical for forming social memories. These parts of the brain develop rapidly in the first few years of life. Experiences with siblings during this time lead to strong memories that persist into adulthood. Even if siblings are separated at a young age, they are still able to recognize each other later in life due to these early neural connections (Sciencedaily, 2021).

Therefore, early experiences with siblings shape the developing brain in ways that allow for long-term recognition and feelings of kinship. This appears to be a common capability across mammal species that supports sibling bonding.

Role of the Mother

The mother cat plays a crucial role in forming early bonds between littermates. As the mother nurses and grooms her kittens in the first weeks of life, they develop a shared scent signature from her saliva and milk. This shared scent helps kittens identify each other as siblings and facilitates bonding. The presence of the mother nursing and caring for the litter also reinforces the connection between littermates as they experience maternal care together. Research has shown that separating kittens from their mother and littermates at an early age can significantly impair social development and lead to poor bonding later in life ( The mother’s continuing presence as kittens grow nurtures close relationships within the litter.

Visual Cues and Recognition

Cats rely on visual cues like appearance and body language to recognize familiar faces, including those of their siblings. While humans primarily use facial recognition, cats depend more on the whole body for identification. According to research, cats utilize key visual markers like the shape of the head, ears, tail, coat pattern, and overall body type to distinguish identity.

Unlike humans who develop specialized facial recognition brain circuitry, cats do not utilize facial features in the same complex way. However, they do show some ability to recognize faces. A study found cats could distinguish their owner’s face from strangers’ faces when shown photographs. But their recognition was based more on the whole head than precise facial features.

While not as advanced as human facial processing capabilities, cats’ whole-body visual recognition allows them to identify siblings if they retain those memories from early bonds formed with their littermates. However, facial recognition is not an innate or hardwired ability in cats like it is in humans. So if sibling cats are separated early on, they may not remember those visual details needed to recognize brother and sister.

Territorial Behavior

Cats tend to be very territorial animals that will readily mark their territory and defend it against unfamiliar cats. However, sibling cats will often tolerate each other in the same territory more than they would unrelated cats

Cats know their siblings primarily through scent familiarity from living together at a young age. Even when siblings are separated as kittens and reunited later in life, they often recognize each other through smell. This can lead to more tolerance and less territorial aggression between siblings versus unrelated cats

Territorial aggression is usually worse between unfamiliar cats of the same gender. So sibling cats of different genders may be less likely to show territorial behavior against each other. However, tensions can still arise between siblings, especially if they did not bond well as kittens or were separated for long periods early on.

Genetic Bonds

Littermates share genetics and are often biological siblings, which intrinsically creates strong bonds between them ( The shared genetics contribute to their ability to recognize each other and form familial connections. Researchers believe genetics play a role in bonding for other highly social species as well, like primates, who can identify kin by sight, sound and smell even when separated at birth (

These genetic factors assist with familiarity and bonding in early development. Kittens who grow up together develop bonds through nursing, cuddling, playing and other shared experiences. Their shared genetics and familiarity lead to ongoing recognition and relationships as adults, even if they become separated.

Strengthening Bonds

Cat siblings that are raised together from a young age often form close bonds as kittens. However, as they grow older, aggression and socialization issues can sometimes occur that may weaken their bond. There are several tips cat owners can follow to help encourage positive associations between cat siblings:

Spend one-on-one playtime with each cat separately. Engage them in interactive play with wand toys, lasers, or other toys they enjoy. This individual attention strengthens their bond with you, which can improve relations between the cats (Source).

Hand feed cat siblings treats or wet food together in close proximity. Feeding cats near each other creates positive associations. Make sure each cat gets treats to avoid resource guarding (Source).

Never punish cat siblings for aggressive behavior between each other. This can weaken their bond. Instead, redirect aggression by separating cats and providing toys for swatting and biting.

Consider pheromone diffusers to help calm tensions between cats. Feline facial pheromones can promote affection and relaxation.

Give cat siblings their own spaces, beds, litter boxes and scratching posts, so they can have alone time when needed.

Consult a vet or animal behaviorist if aggression issues persist. Medication may help in some cases of anxiety or territorial behavior between cats.

With patience and positive reinforcement, cat owners can strengthen the bond between feline siblings over time.


The research and evidence explored in this article reveal some fascinating insights into the relationships between cat siblings. Even when separated at an early age, cats are able to recognize and form social bonds with their littermates later in life. This is likely due to a combination of genetic factors and early imprinting through their mother’s care and scent in the first weeks after birth.

While cats are often portrayed as solitary creatures, studies show they actually retain strong connections to their siblings. Littermates separated at only a few days old have been observed continuing to interact in a friendly manner when reunited as adults. Cats rely heavily on scent cues to identify family members, and can distinguish between their own mother and an unrelated cat of the same breed and coloration.

Understanding how cats form lasting social relationships provides scientific insights into the development of memory, cognition, genetics, and behavior patterns in felines. Though they become independent as they mature, the bonds cats share with their brothers and sisters remain an important part of their social world.

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