Deer Ked, Lipoptena cervi, a biting fly. darkfield photomicrograph

Winged adult deer keds are flying about in early autumn (and sometimes through December) in search of deer. As soon as the fly alights on a host it begins to burrow through the fur, shedding its wings by breaking them off close to their bases. The keds then take a blood meal, mate and after an indeterminate period the female will birth a mature larva which will begin to pupate. After birthing, the female will again feed, mate and produce another larva. It is unclear how many larvae are produced per female.