Black flies are members of the Simuliidae family. Some 1,800 species have been identified to date. These flies are generally grey or black in color and have short legs and antennae. Males generally feed on nectar, while the females also feed on the blood of other animals, just like mosquitoes. All the fossilized black fly that have come to light show that these insects have remained the same ever since they first came into being and have never changed- in other words, they have never evolved. One such fossil is this 45-million-year-old black fly preserved in amber.