I chose this photo from 1000 pieces of photos of guinea pig because it is the most good-looking one. I don't know it is a girl or a boy or a man or a woman. It's hard to discriminate the old guinea pigs from young ones. You see, its eyes are crystal-clear,and it looks smart.Though it 's fat in this picture. My sister has one guinea pig,and she is good-looking as this one.