Kangaroos are herbivores whose diet consists mainly of various plants such as grasses, shrubs and flowers. Some species may also eat fungi and moss. Kangaroos live in groups known as “thugs,” also known as troops or herds. These thugs are usually led by dominant men in the group. Like cows, kangaroos may ruminate food, chew it as a chew, and swallow it again. This behavior is more rare in kangaroos than in ruminants. The kangaroo stomach is different from the stomach of cows and similar animals; although kangaroos and cows have stomachs, the fermentation process in their stomachs is different. Unlike cows, the kangaroo process does not produce too much methane, so kangaroos contribute less to global methane emissions than cows. Kangaroos are usually active at night and early in the morning, but their overall mode of activity is varied. Their rest time is almost entirely limited to the day and night (daytime) mode. Similar to camels, they may last for a while without drinking water because they are relatively inactive during hot days. Since their diet consists of plants, their water needs can be met by the amount of water present in the plants they eat.