Ticks have been known to us since the dwn of history. Aristotle (385-322 BC) believed that ticks were spontaneously generated from grass. Pliny the Elder (AD 23-79) thought that ticks must die after gorging on their victim's blood, because he was labouring under the misapprehension that they had no anus. However, it was not until the late nineteenth century that ticks were suspected of transmitting certain diseases.