Tailed Beast Telepathy

An innate skill possessed by all the tailed beasts, which allows them to communicate with one another mentally. Using this telepathy, the tailed beast can create a dimension within the subconscious of their jinchūriki referred to as the Mental World (精神世界, Seishin Sekai) where they can communicate without outside influences. There are apparently two levels of this subconscious and according to Kurama, once a jinchūriki is further linked with their tailed beast, they will be able to enter this deeper level of their subconscious. This secondary level is not penetrable by others, even if the beasts are being controlled.