Social organisation in red squirrels depends largely on the distribution of important resources such as food, nest sites and mates.

Neither sex is territorial, that is they do not defend areas of forest against other individuals, except during the breeding season when older females are thought to exclude other females from their nest area. By contrast, male ranges overlap extensively with those of other males and females. This lack of territorial behaviour is thought to be due to the unpredictability of food resources in the habitat. However, they do restrict their daily activity to a measurable area – the home range – which, along with individual spacing behaviour, varies according to sexual activity and the abundance, and quality, of food available.