The gray mouse lemur (Microcebus murinus), grey mouse lemur or lesser mouse lemur, is a small lemur, a type of strepsirrhine primate, found only on the island of Madagascar. Weighing 58 to 67 grams (2.0 to 2.4 oz), it is the largest of the mouse lemurs (genus Microcebus), a group that includes the smallest primates in the world. The species is named for its mouse-like size and coloration and is known locally (in Malagasy) as tsidy, koitsiky, titilivaha, pondiky, and vakiandry. The gray mouse lemur and all other mouse lemurs are considered cryptic species, as they are nearly indistinguishable from each other by appearance. For this reason, the gray mouse lemur was considered the only mouse lemur species for decades until more recent studies began to distinguish between the species. The gray mouse lemur is nocturnal, sleeping during the day in tree holes lined with leaf litter or purpose-built spherical nests constructed from dead leaves, moss and twigs. It usually forages alone at night, but may sleep in groups during the day, the composition of which depends on gender and season. Tree holes can be shared with up to 15 other individuals, although males tend to sleep alone while females tend to share nests. (Source: Wikipedia.org, CC BY-SA)