The male black-winged damselfly provides a striking example of an adaptation to sperm competition. Female black-winged damselflies are known to mate with several males over the span of only a few hours and therefore possess a receptacle known as a spermatheca which stores the sperm. During the process of mating the male damselfly will pump his abdomen up and down using his specially adapted penis which acts as a scrub brush to remove the sperm of another male. This method proves quite successful and the male damselfly has been known to remove 90-100 percent of the competing sperm.