A、To survive in the ever-changing weather. B、To facilitate their travel over long distances. C、To adapt themselves to a particul

The saying "blind as a bat" simply isn’t correct. The truth is that all 1,100 bat species can see and often their vision is pretty good, although not as excellent as other night-hunting animals.
    There are two main groups of bats, which are believed to have evolved independently of each other, but both from a common ancestor. The first group, known as "mega bats", are mostly medium-sized or large bats who eat fruits, flowers, and sometimes small animals or fish. These species have distinctive visual centers and big eyes. They use senses of vision and smell to capture their prey. For example, Flying Foxes not only see well during daylight, but can also distinguish colors. They actually rely on their daylight vision and cannot fly during the night with no moonlight. The second group, called "micro bats", are smaller in size and mostly eat insects. These species use echo location to find their way and identify food. Scientists have proven that despite their poorly developed small eyes, these bats still can see during the day. When we consider the nightly lifestyle of these bats, we will see they have to be sensitive to the changing light levels because this is how they sense when to start hunting. Moreover, vision is used by micro bats to travel over long distances beyond the range of echo location.
    So the truth is, there are no bats which are naturally blind. Some species use their sense of hearing more than their eyes as a matter of adaptation to a particular lifestyle, but their eyes are still functional.
    9. What do we learn about mega bats?
    10.How do micro bats find their way and identify food?
    11.Why do some species of bats use their sense of hearing more than their eyes?