Domestic kittens (Felis catus) spend a large portion of their early life with their littermates. If prevented access from these littermates, kittens show issues with social communication skills. Kittens also play with their littermates starting around 4 weeks of age.

Art by Cloude Liu

Reference:

Guyot, G. W., Bennett, T. L., & Cross, H. A. (1980). The effects of social isolation on the behavior of juvenile domestic cats. Developmental Psychobiology, 13(3), 317–329. https://doi.org/10.1002/dev.420130307

West, M. J. (1974). Social play in the domestic cat. American Zoologist, 14(1), 427–436. https://doi.org/10.1093/icb/14.1.427

[Edited by Isabelle McDonald]