Ant

General Info :

Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. More than 12,500 out of an estimated total of 22,000 species have been classified. They are easily identified by their elbowed antennae and a distinctive node-like structure that forms a slender waist.

Ants form colonies that range in size from a few dozen predatory individuals living in small natural cavities to highly organised colonies that may occupy large territories and consist of millions of individuals. Larger colonies consist mostly of sterile wingless females forming castes of "workers", "soldiers", or other specialised groups. Nearly all ant colonies also have some fertile males called "drones" and one or more fertile females called "queens". The colonies sometimes are described as superorganisms because the ants appear to operate as a unified entity, collectively working together to support the colony.

Physique : 

Ants range in size from 0.75 to 52 millimetres (0.030–2.0 in), the largest species being the fossil Titanomyrma giganteum, the queen of which was 6 centimetres (2.4 in) long with a wingspan of 15 centimetres (5.9 in). Ants vary in colour; most ants are red or black, but a few species are green and some tropical species have a metallic lustre. More than 12,000 species are currently known (with upper estimates of the potential existence of about 22,000), with the greatest diversity in the tropics. Taxonomic studies continue to resolve the classification and systematics of ants. Online databases of ant species, including AntBase and the Hymenoptera Name Server, help to keep track of the known and newly described species.

Diet :

Most ants are generalist predators, scavengers, and indirect herbivores, but a few have evolved specialised ways of obtaining nutrition. Leafcutter ants (Atta and Acromyrmex) feed exclusively on a fungus that grows only within their colonies. They continually collect leaves which are taken to the colony, cut into tiny pieces and placed in fungal gardens. Workers specialise in related tasks according to their sizes. The largest ants cut stalks, smaller workers chew the leaves and the smallest tend the fungus. Leafcutter ants are sensitive enough to recognise the reaction of the fungus to different plant material, apparently detecting chemical signals from the fungus. If a particular type of leaf is found to be toxic to the fungus, the colony will no longer collect it. The ants feed on structures produced by the fungi called gongylidia. Symbiotic bacteria on the exterior surface of the ants produce antibiotics that kill bacteria introduced into the nest that may harm the fungi.

Distribution:

Ants are found on all continents except Antarctica, and only a few large islands such as Greenland, Iceland, parts of Polynesia and the Hawaiian Islands lack native ant species. Ants occupy a wide range of ecological niches, and are able to exploit a wide range of food resources either as direct or indirect herbivores, predators, and scavengers.

American Bison

General Info :

The American bison  also commonly known as the American buffalo, is a North American species of bison that once roamed the grasslands of North America in massive herds, became nearly extinct by a combination of commercial hunting and slaughter in the 19th century and introduction of bovine diseases from domestic cattle, and has made a recent resurgence largely restricted to a few national parks and reserves.
Two subspecies or ecotypes have been described: the plains bison (Bison bison bison), smaller in size and with a more rounded hump, and the wood bison (Bison bison athabascae)—the larger of the two and having a taller, square hump.

Physique :

A bison has a shaggy, long, dark brown winter coat, and a lighter weight, lighter brown summer coat. As is typical in ungulates, the male bison are slightly larger than the female and, in some cases, can be considerably heavier. Plains bison are often in the smaller range of sizes, and Wood bison in the larger range. Head-and-body length ranges from 2 to 3.5 m (6.6 to 11.5 ft) long, the tail adding 30 to 91 cm (12 to 36 in). Shoulder height in the species can range from 152 to 186 cm (60 to 73 in). Typical weight can range from 318 to 1,000 kg (700 to 2,200 lb).

Diet :

Bison are herbivores, grazing on the grasses and sedges of the North American prairies. Their daily schedule involves two-hour periods of grazing, resting and cud chewing, then moving to a new location to graze again.

Distribution :

Their historical range roughly comprised a triangle between the Great Bear Lake in Canada's far northwest, south to the Mexican states of Durango and Nuevo León, and east to the Atlantic Seaboard of the United States (nearly to the Atlantic tidewater in some areas) from New York to Georgia and per some sources down to Florida.
American bison live in river valleys, and on prairies and plains. Typical habitat is open or semi-open grasslands, as well as sagebrush, semi-arid lands and scrublands. Some lightly wooded areas are also known historically to have supported bison. Bison will also graze in hilly or mountainous areas where the slopes are not steep. Though not particularly known as high altitude animals, bison in the Yellowstone Park bison herd are frequently found at elevations above 8,000 feet and the Henry Mountains bison herd is found on the plains around the Henry Mountains, Utah, as well as in mountain valleys of the Henry Mountains to an altitude of 10,000 feet.