There are two main groups of bats – Megachiroptera and Microchiroptera.
The Megachiroptera are medium-sized to large bats that eat fruits, nectar, and sometimes small animals or fish. These species have pronounced visual centers and big eyes as they use senses of vision and smell to capture their prey. For example, Flying Foxes are able not only to see well during daylight, but also can see in color. They actually rely on their daylight vision and cannot fly during moonless nights.
The Microchiroptera are smaller in size and mostly eat insects. These species use echolocation to navigate and identify the food. However, despite their poorly developed small eyes, these bats still can see during the day. Vision is used by micro bats to navigate over long distances, beyond the range of echolocation.