The fruit fly Drosophila (also called the vinegar fly or pomace fly) has been used more than any other animal in sex experiments and research into various aspects of genetics.

It was first established as a laboratory animal in America during the first decade of the twentieth century. It proved an ideal subject for breeding experiments since it reproduces prolifically in milk bottles and 25 generations can be obtained within a year. The chromosomes have been observed directly and a wealth of genetic information has been obtained by a variety of experimental procedures. Drosophila has made a fundamental contribution to the science of cytogenetics in general and to the genetics of sex determination in particular.