Description of the biotope; developmental stages in Ixodes ricinus as well as infestation with the spirochete (Borrelia burgdorferi); removal of ticks; documentation of patients with symptoms at various stages of Lyme disease (erythema migrans, facial paresis, gonarthritis); ticks as vectors; life cycle of the three-host tick; hatching, larva, molting, nymph, ecdysis, male or female adults, copulation, oviposition; mice as important hosts for sub-adult ticks, deer for adult ticks; developmental cycle of Borrelia burgdorferi and correlation with the life cycle of the tick; the principle of "zooprophylaxis"; with time-lapse, micro- and macrocinematographic shots and animated sequences.