Lyme disease is caused by bugs.
Lyme disease . The most common sign of infection is an expanding area of redness on the skin , known as erythema migrans , that begins at the site of a tick bite about a week after it has occurred . Lyme disease is transmitted to humans by the bite of infected ticks of the Ixodes genus . Ticks are small arachnids , part of the order Parasitiformes .