In Splatoon, what is the age that inklings can freely change between squid and humanoid forms?

In the game "Splatoon," Inklings can freely change between their squid and humanoid forms once they reach the age of 14. This age is significant as it represents the transition from childhood to adolescence for these fictional characters. At this point, Inklings have matured enough to control and manipulate their ink-based abilities, allowing them to seamlessly switch between their two forms during gameplay and strategic battles.