On Monday, October 17, 2016 at 10:14:05 AM UTC-4, JohnDoe wrote:
Hi, I found mice nests in my basement insulation as well as mice droppings on
the basement floor. My basement is unfinished. Are mice attracted to dark,
unfinished areas? Would it help solve the mice problem if I finish my basement.


Yeah, that'll do it. Mice hate nice rooms. ;-)

The issue is not finished or unfinished, the issue is access.

The critters have found a way into your basement and unless you seal
up those access points, it won't matter what you do to the interior space.
Maybe they'll avoid the finished spaces due to noise and light, but
that won't stop them from nesting inside the walls.

A quick story finished spaces and mice...

A friend moved into his grandma's house when she passed away. It was brick
farmhouse built in the late 1800's. I was helping him gut the kitchen
and when we removed the interior walls we found the stud bays loaded
with all sorts of mice related debris. Shells from acorns and other nuts,
nests, droppings, carcasses, etc. Each bay was filled at least 2 feet from
the floor. He was expecting the worse and had already bought a large
supply of heavy duty dust masks. We probably should have been wearing
respirators, but it's 20 years later and (tic) I'm (tic) OK (tic) I'm
(tic) OK. (tic) I'm (tic) OK. (tic)