Book with large black hands / arms and glowing purple insects
I'm looking for a book from approx 20 years ago. The two major details I remember are large black hands and arms (no body) and glowing purple insects (I think they were fireflies).
One scene I recall is a large black hand comes out of the woods and attacks a family in a car.
Set in a small town in the US.
Not aliens. There may have been an unground facility of some kind.
It's not The Taking by Dean Koontz