Ticks aren’t visible to the naked eye

False. Although very small, ticks are visible to the naked eye.

A tick’s size varies according to the species, the life-stage of the tick and whether it has fed or has not fed. Unfed adult ticks range in length from 2 mm to 20 mm depending on species. Blood-engorged females may be 25 to 30 mm in length and weigh up to 100 times their pre-engorgement weights (5).

Ixodes ricinus larvae are approximately 1mm (size of a poppy seed); nymphs 2mm, unfed adult ticks are 2.4 - 3.6mm whilst engorged females can reach up to 11mm.