By 20 weeks (the 22nd week of pregnancy), the mother can feel the fetus move. It has eyebrows and hair on its head. Its entire body is covered in fine, downy hair. A greasy substance called vernix protects the skin. The fetus practises swallowing and digesting fluid, and can even tell sweet tastes from bitter ones. An ultrasound scan may now reveal whether the fetus is a boy or a girl.