When we are young, we learn that
tigers and sharks are dangerous animals. We might be scared of them because
they are big and powerful. As we get older, however, we learn that sometimes
the most dangerous animals are also the smallest animals. In fact, the animal
that kills the most people every year is one that you have probably killed
yourself many times: the mosquito.
While it may seem that all
mosquitoes are biters, this is not actually the case. Male mosquitoes eat plant
nectar. One the other hand, female mosquitoes feed on animal blood. They need
this blood to live and produce eggs. When a female mosquito bites a human
being, it transmits a small amount of saliva into the blood. The saliva may or
may not contain a deadly disease. The result of the bite can be as minor as an
itchy bump or as serious as death.
Because a mosquito can bite many
people in the course of its life, it can carry diseases from one person to
another very easily. Two of the most deadly diseases carried by mosquitoes are
malaria and yellow fever. More than 700 million people become sick from these
diseases every year. At least 2 million of these people will die from these
diseases.
Many scientists are working on
safer and better ways to kill mosquitoes, but so far, there is no sure way to
protect everyone in the world from their deadly bites. Mosquito nests can be
placed over beds to protect people against being bitten. These nets help people
stay safe at night, but they do not kill any mosquitoes. Mosquitoes have many
natural enemies like bats, birds, dragonflies, and certain kinds of fish.
Bringing more of these animals into places where mosquitoes live might help to
cut down the amount of mosquitoes in that area. This is a natural solution, but
is does not always work very well. Mosquitoes can also be killed with poisons
or sprays. Even though these sprays kill mosquitoes, they may also harm other
plants or animals.
Although mosquitoes may not seem
as scary as larger, more powerful animals, they are far more dangerous to human
beings. But things are changing. It is highly likely that one day scientists
will find a way to keep everyone safe from mosquitoes and the diseases they
carry.
Which of the following best
summarizes the information in paragraph 4?
