So the book starts off with the family deciding to take a trip to a cabin in the woods. The daughter also has her best friend with her.
The points I remember from the book:
The father has an affair with the daughter's friend
At night, the aliens come, they look like giant flying insects like bees with abdomens that glow different colours
They manage to get a hold of the dad while he's fighting them off and he later returns zombie-like and talking for the aliens
The aliens eventually get fought off one by one (I think)
I read this book in the early 2000s but it may even have been around way before then as I found it at a second hand book store.