Generally, when the temperature drops below 10°C, the European swamp turtle enters a lethargic phase, burying itself in the mud near the river bank. When the temperature is lower than 5 ℃, the European sea turtle enters the hibernation period.

European sea turtles have strong cold tolerance and are basically omnivorous turtles, mainly feeding on aquatic invertebrates and also feeding Aquatic plants, including small fish, shrimp, raw meat, Tenebrio molitor and other animal bait, together with various vegetables, fruits and other plant bait. European swamp turtles become more vegetarian when they reach adulthood.