Okay kiddo, let me tell you about the testudo formation. It's a way that soldiers used to move around in the past, especially the Roman soldiers.
Imagine you and your friends are going on a treasure hunt. You would usually walk in a line, right? But what if there were bad guys throwing bouncy balls at you? You might want to huddle together and create a shield so that you can protect each other, right?
That's what the testudo formation is! It's like a strong shield that the soldiers make to protect themselves from things being thrown at them. They stand close together in a tight row, side by side, and hold their shields up high to protect their bodies. They also put their shields above their heads to create a roof, like a turtle's shell.
Then they move forward slowly and carefully, making sure that everyone stays together and everyone is protected. It's a really good way to stay safe in battle.
So that's the testudo formation, kiddo! It's a way that soldiers used to protect themselves a long, long time ago.