Eastern box turtles have a ferocious appetite, even as babies. Some people are concerned about feeding them insects that are the size of their heads, but these guys will gladly oblige in tearing larger meals apart.
And they need to learn to at this age...prey identification, opportunity, speed, dexterity...all of that gets hardwired into the brain for a lifetime. It becomes very hard for adults to learn how to intentionally hunt and eat properly if they miss out on this instinctive phase.