well i found a fake turtle its sopposed to be a sea turtle but its yellow and like 3 inches tall i thought it would be funny to mess with my lil res turt and but it in her tank i guess mine is an aggressive turt cuz the next day i noticed little parts of his head was missing. but i guess thats a good way to tell if your turt is aggressive just do that nexttime just incase if your going to buy a new res.