Pond turtles are 'ectothermic'. That word means their bodies don't make their own heat - they need warmth from outside. So every morning, they crawl out of the cool water onto a log or a stone and bask in the sunshine until they are warm enough to swim and hunt.
Underwater, they are surprisingly fast. They have webbed feet and can hold their breath for a long time. They eat snails, small fish, insects and water plants. Their sharp little beak (instead of teeth!) helps them break their food into pieces.
Every June, female pond turtles climb out of the water and dig a hole in soft sandy earth nearby. They lay six to ten leathery, ping-pong-ball-sized eggs in the hole and gently cover them up. The babies hatch around three months later and have to find their own way back to water.
Pond turtles are slow growers. They can live for 50 or 60 years - sometimes even longer. A pond turtle alive today in Serbia may have been swimming in the same river when your grandparents were children.