Pygmy is the smallest mammal in the world. Pygmy shrew is the smallest known mammal by mass, weighing only about 1.8 grams (0.063 oz) on average Its body is about 5 cm (2 in) long including a 2-cm-long tail, and it weighs about 2.0 to 4.5 g (0.071 to 0.159 oz). Its fur is generally a reddish or grayish brown during the summer, and a white-gray color during the winter. The underside is generally a lighter gray. This animal molts about twice a year, once during late summer, and again during the spring. It has a narrow head with a pointed nose, and whiskers. The eyes are small and well hidden.