Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these other species were increased, more of the larvae would be feeding on uninfected hosts
the number of ticks acquiring the bacterium would likely decline.
Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed