Ornithodoros species are soft ticks (Family Argasidae). Included in this genus is Ornithodoros moubata, an important vector of tick-borne relapsing fever (TBRF) in humans in parts of Africa. Ornithodoros moubata transmits the spirochaete bacterium Borrelia duttonii, which causes TBRF. (Louse-borne relapsing fever [LBRF], the occurrence of which has been greatly reduced in recent decades, is caused by B. recurrentis, which genetic studies suggest may be a louse-adapted form of B. duttonii.) TBRF remains a major cause of child mortality in some African counries. TBRF may also be caused by B. crocidurae (transmitted by the soft tick O. sonrai) in West Africa and B. hispanica (transmitted by the soft tick O. erraticus) in North Africa, with B. duttonii dominating in East Africa, but this is not clearly established. (Cutler et al. 2009)

Like other argasids, Ornithodoros ticks have multihost life cycles. Argasid ticks have two or more nymphal stages, each requiring a blood meal from a host. Unlike the ixodid (hard) ticks, which stay attached to their hosts for up to several days while feeding, most argasid ticks are adapted to feeding rapidly (for about an hour), then dropping off the host.

(Centers for Disease Control Parasites and Health website)

Resler et al. (2009) studied the movements of spermatozoa in the reproductive tract of female Ornithodoros moubata soft ticks, which become more pronounced after a blood meal.