The heads of bats are strangely sculptured, some being smoothly
contoured and shaped like those of little foxes; others appear like
miniature bulldogs; and still others have curious cartilaginous
nose-leaves upright on the muzzle. Some have the entire face molded
into a hideous mask repulsive to look upon.
Their habits are equally varied to meet special conditions: Some are
eaters of fruit alone; others feed solely upon insects, while others
bite other mammals, including man, for the purpose of drinking the
oozing blood, upon which they subsist. All are nocturnal, but some
appear late in the afternoon, before the sun sets; most species,
however, wait until the shades of night have covered the earth.
Throughout the world the majority of the species of bats feed upon
insects, but there are many fruit-eaters. The teeming insects and
plant life of the tropics afford a never-failing food supply, and the
center of abundance of these animals is found there. In some localities
between twenty and thirty kinds of bats exist, with such vast numbers
of individuals that the bat population far outnumbers all other kinds
of mammals combined.