Andrea Boers, age 10, of E1 Cajon, Calif., for her question:
DO BIRDS HAVE GOOD HEARING?
Birds have highly sensitive hearing. They can usually hear even the slightest sound. Scientists call the hearing of birds "acute" because it is so sharp.
You won't find the shell like cups on each side of a bird's head the way you will with humans and with other animals. Birds do not have outer ears. But even so, most of the time they can hear extremely well.
Inside a bird's head, in most cases, one on each side, you'll find an eardrum, a middle ear and an inner ear. Birds can hear whether flying or standing still.
Some birds, such as the owl, have hearing that is even more acute than the average bird. An owl's hearing is so remarkably sensitive that the bird can use the sense of sound to locate and catch a mouse even in complete darkness.
Birds also have acute senses of sight although their abilities to taste and smell are not as well developed as are their abilities to hear and see.
Many night flying birds need only 1/100th as much light as humans need to see. Also, many birds are able to change the focus of their eyes quickly by means of muscles that actually change the shape of the lenses in their eyes.
Birds don't rate too high when it comes to the sense of intelligence. Although most birds can learn a little, they aren't especially bright.
There are about 9,000 different kinds of birds, and you'll find them living in all parts of the world.
Most birds are valuable to man. Chickens and other poultry provide meat and eggs for food. Also, birds help farmers by eating insects that attack the crops. A few birds eat grain and fruit, but the good that birds do more than makes up for the damage they cause.
All birds hatch from eggs, have two legs and bills or beaks.
Birds have built in "air conditioning," meaning that some of their bones are hollow and their bodies have air sacs or air pockets. Their lungs pump cooling air into these sacs and bones. The hollow bones also make birds lighter so they can fly easily.
Birds eat more in relation to their size than most people do. The smaller the bird, the more it eats compared with its weight.
Some baby birds in one day eat nearly their own weight in food. A pigeon may eat food equal to 1/20th of its weight in a day. To equal this appetite, a person weighing 180 pounds would have to eat nine pounds of food in a day. The average person eats only about three pounds of food a day.
Birds have been very popular with man since ancient times.