Many have no eyes or eyes that are poorly developed. Eyes are not necessary because of the lack of light. Since eyes require food energy to maintain, and are very prone to injury, an eyeless cave fish can survive longer with less food than a fish that has eyes. What the troglobites have lost they make up for with longer legs and antennae, or feelers, and with adaptations that enable them to go for long periods of time with little food. Your friendly neighborhood bat.
Bats are tiny mammals that are often feared by many people.
Bats are one of the most misunderstood animals. The truth is that bats are gentle, intelligent animals that are quite timid when it comes to interacting with humans. They are one of the most numerous and diverse orders of mammals. The total world population of bats is more than ten billion. About 1,000 species are recognized.