Mouse lemur (MICROCEBUS MURINUS) is one of the smallest primates. It's weight is about 60 g. Fat-tailed lemur (CHEIROGALEUS MEDIUS) (LEMURIDAE) is larger. These nocturnal species inhabit tropical forests of Madagascar. They are common in secondary forests where they construct spherical nests from leaves in foliage and in hollows of trees. There is a decline of activity during the winter. Before it fat is accumulated in the tail. Both species eat insects, spiders, frogs and lizards and also fruits, flowers, nectar. These animals live alone or form pairs.