When a turtle is hungry, the turtle will swim slowly. But when they are hungry, they become more active, swimming around and sometimes even lunging for food. When a turtle is hungry, it will make a slight sound, similar to a slow groan. Turtles will show some obvious food-seeking gestures, such as extending their necks, opening their mouths, etc.
When a turtle is hungry, sometimes It will slap the water with its front paws, which is a sign of asking for food. If your turtle suddenly stops eating, or eats less, it may be because they are starving to the point where they can no longer eat normally. Please note that these signsdoes not apply to all tortoises, as different species of tortoises have different behaviors and habits. Also, don't overfeed your turtle, as overfeeding can lead to obesity and other health problems.