Cats are social creatures and will always want some form of companionship. It is their litter mates that will grow with them and develop a bond that can be observed over the weeks that are to come. The relationship between siblings is an amazing feat as new born kittens that are barely able to move become active kittens.
They will begin to show signs of social development when they start to interact with one another. Grooming, playfighting and even meal times will all be part of their growing and relationship building. Allowing a kitten to live with its littermates will be crucial in learning about how it should play with other kittens and people in the household. Kittens will not be aware of aggression levels and levels of force to exert when playing.