I am going to go out on a limb and guess that the deer tick population has increased because the deer population has increased.
They are regularly seen walking down city streets here now. Bears wandering into peoples’ yards are now not unusual. Recently they captured a bobcat aboard a popular tour boat. Not long ago a coyote was shot within a mile of downtown.
Start cleaning up the environment and all the pesky wildlife returns. Go figure.
Maybe so, but I also attribute the increase to warmer, and inconsistent winter temps which limit the amount of 'winter kill' of ticks and host deer populations,
and a decrease in the number of deer hunters with the older population not passing on hunting skills to youngsters.
Actually, ticks will prey on any warm-blooded mammal (humans, dogs, squirrels, possum, etc.),
and as long as the host is mobile, ticks can trans-locate further afield.