Ticks, along with mites, belong to the subclass Acari, and are found mainly in wooded areas in the spring and summer. In Europe, they are the most common vectors of infectious diseases in humans and animals. They can transmit bacteria, viruses and parasites. In France, the main disease transmitted to humans by ticks is Lyme disease. ANSES studies tick-borne pathogenic agents in order to identify and characterise them and more effectively combat them.