Anatomy of the meerkat.
Body Features
Eyes
The dark markings around a meerkat's eyes act like built-in sunglasses, deflecting the rays of the desert sun and therefore allowing them to see their surroundings clearly. They also serve well against some predators, the rings make the meerkat's eyes appear bigger and more threatening. The eyes themselves have horizontal pupils, giving them a greater perception of depth. Meerkats are farsighted mammals, they can spot a bird of prey over 1km (approximately 0.6 miles) away. However, their vision up close is rather blurry, much like a camera out of focus. For this reason, they use their sense of smell to find prey and identify other meerkats rather than using their eyes. Some wild meerkats have been able to survive with just one functional eye.
Ears
Meerkats have small, round, dark-coloured ears which are set very low on each side of the head. The insides of the ears are crescent-shaped and closeable. When digging meerkats will always close their ears to keep out dust and dirt. However, even with closed ears meerkats are able to pick up alarm calls. The shape of the meerkat's ear is considered to be somewhat unique among members of the mongoose family, as the majority of the meerkat's relaties have pointed ears.
Nose
The meerkat has a tapered snout that comes to a point at 2-3 inches (5-8 centimeters). Pups are born with bright pink noses, but as they age, the coloration turns largely to black. They have a powerful sense of smell which is used to identify other meerkats from friend and foe, to sniff out prey underground and to determine the receptiveness of females. From a scent meerkats can also determine how recent a predator or rival meerkat has been in the area and what kind of animal it is or, in the case of a rival meerkat, what group they came from. Meerkats use smell to identify other meerkats.
Mouth
Being carnivores meerkats have incredibly sharp teeth, designed for crunching through the exoskeleton of insects (their main prey item). Altogether meerkats have around 36-40 teeth, this includes 4 canines, 12 incisors, 12-16 premolars and 4-8 molars. They will use their fangs not only for catching and killing prey, but also for combat against rival meerkats and occasionally predators. When facing rivals, meerkats will lock on to their foe (sometimes for 4-5 minutes). This "latching" strategy has also been observed in some captive meerkats to their keepers or owners, in which case meerkats can only be dislodged by the use of water, as even the strength of another person will seldom pry a meerkat off.
Fur
Depending on the sub-species, a meerkats fur can range from dark brown, light grey, pale tan, medium brown and bright orange. Southernly species that thrive in green scrublands tend to be dark brown in colour, whilst those in the Kalahari Desert where the terrain is brighter-coloured are generally light brown or orange. Meerkats living in the Namib Desert have light tan coats. Most captive meerkats are a sub-species which has a light grey fur coat. There has only been one known completely "white" coloured meerkat, which lives today at Adelaide Zoo, and one entirely bright orange meerkat (including claws and eye-patches) called Lucifer. There has also been cases of meerkats having odd reddish patches on their faces, both in captivity and the wild. The meerkat's fur is a great conductor of heat as they don't sweat and can moderate their temperature well. However, their fur is not as well suited for cold conditions, particually at night.
Claws
The meerkat's non-retractable claws reach a length of 2 centimeters (0.8 inches) long. Each paw has 4 claws, adding up to 16 weapons altogether. They are prime digging tools, allowing the meerkats to shift their own body weight in sand in a matter of seconds. They are also, occasionally, used to scratch foes in combat or self defence. However, meerkats prefer to use their fangs over their claws when it comes to battling.
Legs, Forearms and Feet
Meerkats have extremely powerful forearms, made to push away large amounts of and rocks. Their legs are also reasonably strong, allowing them to stand on their hind feet (with the assistance of their tail). Although much of the meerkats foot is padded, they will only stand on their toes where the padding is at its thickest. This design allows them to run across terrain at speed of up to 20 miles per hour. Meerkats will use their legs, forearms and feet to scale rocks, bushes, logs and even sometimes trees to keep a lookout for danger. However, these sentries are almost always within 5m of a bolt hole, allowing them to be one of the first into the hole should a predator appear.
Tail of young meerkat
Tail
The meerkat has a thin, tapered tail that measures 7 to 10 inches in length (or 17 - 25 centimeters long). The tail is brownish in color (bright orange for a different sub-species) and has a distinctive black tip. Unlike other members of the mongoose family, the meerkat's tail is not bushy but slender. This gave rise to one of the meerkat's common names; Slender-tailed Meerkat. The meerkat uses its long tail for balance when it stands at attention on its hind legs. It will also hold its tail high and straight when excited, alarmed or assertive. The tail is also used during snake-mobbing, the tip of the tail acts like the meerkat's head, telling the snake to strike the tail rather than the real head. It helps the meerkats avoid a potentially fatal bite. The tail is also important part of meerkat body language. If it is down, a meerkat is calm or submissive. The tail is almost always raised during combat or play behaviour.
Scent Glands
Scent-marking is a major part of meerkat life. Meerkats use smell to establish territory and family members. It can also be a form of bonding. Meerkats have scent glands on their cheeks and in the anal region. Cheek-marking is generally only used between group members, whereas anal-marking is used for all forms of scent-marking. The anal gland is a large empty-looking hole in the meerkat's nether region when not in use. When scent-marking a pink buldge emerges from the hole. This gland is present on both males and females, but is larger on older, dominant males. Meerkats will also occasionally use defecation, urine and saliva to claim territory.