Not all deer ticks are infected. Ticks can attach to any part of the body, but more often hidden and hairy areas such as the groin, scalp, and armpits. Scientists have discovered that the ticks are more likely to transmit the bacteria during their nymph stage because they are so small and rarely noticed. Larvae are too small and undeveloped, and adult ticks are most active during the winter when there is less outdoor activity. Ticks make contact with their hosts when the host brushes against a blade of grass or shrubbery.
Ticks crawl to their desired spot on the body, sometimes from the foot to the scalp unnoticed.
Ticks feed on blood by inserting their mouths into the skin, not their whole bodies. They are slow feeders so a meal could last for several days. It is during this feeding when B. burgdorferi is passed from tick to host. The ticks must be attached and feeding from the host for at least 24 hours in order to transmit. The cylindrical shape of the bacteria allows it to wriggle into tight places, like between cells, it's movement much like a snake and aided by flagella and axial filiments.