Stories about ticks leaping on their victims from trees are absolutely misleading. In fact it is very opposite. Ticks are very patient and wait for their host lying in grass. For search, they use higly sensitive senses.
Today, for sure, nobody believes that ticks leap on their victims from trees. Very little people know how the ticks search for their hosts. In contrast to mosquito, the tick does not actively search for host, but it very patiently wait for it. It scales blades of grass or higher vegetation where they hold with hind legs while front legs uses like antenna turning to sides. The main source of information for the tick are physical and chemical perceptions from environment. There are special depressions on last segment of first pair of legs called Haller´s organ where a huge number of sensors is hidden. For the first, it reacts on odor and then chemical signals which are emitted by each animal including people. Mechanical signals like shakes caused by oncoming host are perceived in closer distance by the tick. When host brush against vegetation where the tick is waiting, it can stick to host. This thing is frequently used in sampling of tick from environment called flagging. The tick is stuck to flannel cloth resembling animal fur. The same thing can happen when we are walking with baby carriage, therefore it is better to use repellent bracelet or spray repellent.