Judging from the figures ([363], [364], [365]), are the members of this order better suited for attack, active resistance, passive resistance, or concealment when contending with other animals? The ant-eater’s claws (Fig. [364]) on the fore feet seem to be a hindrance in walking; for what are they useful? Why are its jaws so slender? What is probably the use of the enormous bushy tail? The nine-banded armadillo (Fig. [365]) lives in Mexico and Texas. It is omnivorous. To escape its enemies, it burrows into the ground with surprising rapidity. If unable to escape when pursued, its hard, stout tail and head are turned under to protect the lower side of the body where there are no scales. The three-banded species (Fig. [366]) lives in Argentina. Compare the ears and tail of the two species; give reasons for differences. Why are the eyes so small? The claws so large? Order______. Why? ______.
Fig. 366.—Three-banded Armadillo (Tolypeutes tricinctus).
Insect Eaters.—The soft interior and crusty covering of insects makes it unnecessary for animals that prey upon them to have flat-topped teeth for grinding them to powder, or long cusps for tearing them to pieces. The teeth of insect eaters, even the molars (Fig. [368]), have many sharp tubercles, or points, for holding insects and piercing the crusty outer skeleton and reducing it to bits. As most insects dig in the ground or fly in the air, we are not surprised to learn that some insect-eating mammals (the bats) fly and others (the moles) burrow. Are the members of this order friends or competitors of man?
Fig. 367.—The Mole.
Fig. 368.—Skeleton of Mole. (Shoulder blade is turned upward.)
Why does the mole have very small eyes? Small ears? Compare the shape of the body of a mole and a rat. What difference? Why? Compare the front and the hind legs of a mole. Why are the hind legs so small and weak? Bearing in mind that the body must be arranged for digging and using narrow tunnels, study the skeleton (Fig. [368]) in respect to the following: Bones of arm (length and shape), fingers, claws, shoulder bones, breastbone (why with ridge like a bird?), vertebræ (why are the first two so large?), skull (shape). There are no eye sockets, but there is a snout gristle; for the long, sensitive snout must serve in place of the small and almost useless eyes hidden deep in the fur. Is the fur sleek or rough? Why? Close or thin? It serves to keep the mole clean. The muscles of neck, breast, and shoulders are very strong. Why? The mole eats earthworms as well as insects. It injures plants by breaking and drying out their roots. Experiments show that the Western mole will eat moist grain, though it prefers insects. If a mole is caught, repeat the experiment, making a careful record of the food placed within its reach.
