Bat is the only flying mammal on planet earth. Ranging from minutest bat to large Flying Foxes of Africa, bats make up almost 1,000 species, which means one-quarter of all mammal species. Most bats belong to the suborder Microchiroptera and fly at night, using a sound-radar system to catch small aerial insects. In temperate regions they survive winter’s lack of food by hibernating. The suborder ‘Megachiroptera consists of the larger bats and the fruit bats. Nearly one-third of all bats live on fruits and the nectar of flowers, especially, the Egyptian Fruit bats (Rousettus aegyptiacus).
 

Fruits such as figs and dates when fermented produce ethanol, or drinking alcohol. As these fruits ripen a small concentration of ethanol gets accumulated, which proves toxic for the bats. Even concentrations of less than one percent ethanol can make fruit bats sluggish against predators, and hamper their ability to avoid danger.

The scientist Sanchez told Live-Science how drunken bats sober up and how for some bats, " sugar taste proves better than others. The perception of sweetness versus bitterness may vary according the type of sugar and the amount of ethanol consumed. The combination of sucrose and ethanol may just have tasted better than either ethanol and fructose, or ethanol and glucose."