I did some searching after reading this article, apparently only small mammals (not deer, though ticks often feed on deer and then lay eggs) can pass the bacteria to ticks (95% from the white footed mouse). And ticks do not pass it on their young. Wow reading about Lyme for 20 yrs and never knew this (I have had it six times). For 30 years these are the only mice caught in our home, just one house mouse. So I would say it depends on a number of factors (article states they are not usually found in homes).