Cat relationships with other cats
Close distance means closer relationship
How to define “close”? Here are 3 reference values:
A 2003 paper believes that if the distance between two cats is less than 1 meter, such as sleeping in the same bed, it is considered a relatively close relationship;
The “Basic Behavior Guidelines for Cats” written by Manchester Metropolitan University in 2015 proposes that if the distance between two cats is less than the sum of their body lengths (the distance from the back of the head to the base of the tail), it is a sign of intimacy and friendship~
A 2023 Slovak paper believes that cats who have zero distance and close contact and can sleep next to each other are true friends.

Each of the three values has its own basis. Generally speaking, as long as the distance between two cats is less than 1 meter, they are considered friendly and intimate.

In addition to looking at the distance, the cats’ behavioral interactions can further judge their feelings:
They will lick each other’s fur
Licking and exchanging scents can enhance contact and strengthen familiarity. However, mutual licking is proof of a good relationship. If it is one-sided licking, it may be a dominant behavior.

Playing will give your partner some room
Cats have strong explosiveness but lack endurance, so they often have “half-time breaks” when playing.
A study by the University of Veterinary Medicine and Pharmacy in Košice, Slovakia, pointed out that if a cat wants to continue playing after a break, but the other cat doesn’t want to play anymore, they choose to escape or refuse instead of directly escalating into verbal attacks. Both parties have a sense of propriety and tacit understanding, which is a symbol of a stable relationship.

When resources are sufficient, they will share them
When resources are sufficient, cats with close relationships can share resources, such as food, territory, cat climbing frames, toys, etc.
Greeting each other when meeting
For example, when stray cats meet in the wild, or when new cats meet after being quarantined at home, cats will raise their tails, slowly approach each other, sniff each other, and rub their bodies or heads against each other, which are all friendly greetings.