Tortoise formation is a military tactic used primarily by infantry units. In this formation, soldiers arrange themselves in a tight, protective cluster, resembling a tortoise shell. This setup allows for enhanced defense against enemy fire while maintaining the ability to move as a cohesive unit. The formation is particularly effective in situations where troops need to advance under heavy fire or when they are vulnerable to attacks from multiple directions. By presenting a united front, soldiers can better protect themselves and support one another, similar to how a tortoise withdraws into its shell for safety.