Ticks are external blood-sucking parasites that feed on a variety of hosts including livestock, wildlife and humans. The most common tick in the UK is the sheep tick (Ixodes [I.] ricinus) which is indiscriminate, feeding on a wide range of hosts, from birds to small and large mammals, including humans, whereas many other species of ticks feed more selectively on specific animal species. The sheep tick can carry pathogens responsible for several diseases including louping ill (LI), tickborne fever (TBF), babesiosis (red water), Lyme disease, tick pyaemia and tickborne encephalitis (TBE).