Mammals can protect themselves from their natural enemies in various ways. One of the most obvious protective measures is to run away. Kangaroos and hares, for instance, have long hind legs that give them good speed in a bounding escape flight. The hoofed mammals have slender, elongated, running-type legs that lift the body high off the ground; the animals run on their toenails, which are modified into hoofs.
An escaping mammal, if pressed too closely by an attacker, may seek to defend itself. Various methods are employed. The anteaters and sloths lash out with their long, strong claws; rodents and opossums bite their enemies. Hoofed mammals kick out with their feet, or use their tusks, horns or antlers.
Sometimes, instead of running away, many mammals may freeze on the spot. This is common with young fawns; their lack of movement and their dappled coat generally cause them to be overlooked by a predator. Hares will remain motionless until one comes close to them; then they bound away in a zigzag flight. The opossum "plays dead," lying limp with eyes closed and tongue hanging out of its partly opened mouth.
Many of the smaller mammals move about only at night or under the cover of vegetation or under fallen leaves and other debris of the forest floor. The large cud-chewing hoofed mammals come out into the open to feed rapidly. They then quickly return to cover, where they chew the cud and digest their food at leisure and in security.
Armadillos and pangolins are armored with horny plates or scales. When danger threatens they roll up so that only the protected surfaces of the body are exposed to an attacker. Hedgehogs, porcupines and spiny anteaters are protected by hairs that are modified.into sharp spines or quills.
Civets, mongooses and skunks spray an attacker with an evil-smelling liquid — a secretion from modified sebaceous glands in the region of the anus.
Many mammals are patterned or colored in such a way that they blend well with the background. If they refrain from moving, it is usually all but impossible to make them out. For example, the white winter coat of many weasels, foxes, hares and lemmings blends with the snow. Many desert mammals are pale buff or tawny, "melting in" beautifully with the desert soils.
