SOLVED. Horror: Shadowy hidden creatures. [s]

[R.]

This book was Published I believe in the 80s or 90s Maybe late 70s.
Was about a guy who could see these creatures out of the corner of his eyes or indirectly looking at them I believe(ie Mirror, reflection)
They hid as black shadowy objects like Tire rubber debris on highways or roads, in the shadow of objects, anything like black, shadowy or vague.
It took partly in America nd partly in Africa(If I remember correctly)
Plot: Was kind of like these shadowy creatures were invading our world, do not remember if Alien, Demonic or Planar/Dimensional creatures.
He I believe teams up with a women and possibly her child later in book.
there was a seen of them on a highway and the tire debris was the creatures.
Sorry that's all I can remember, I do remember it was really really good.
Thank you all for any help you can provide.

[R.]

May of had Dark or Darkness in title.

[Scott]

Into the Out of by Alan Dean Foster

[R.]

That’s it!
Wow, thank you been looking for this for years. I hope it is as good as I remember.
Thank you again.

[Scott]

You''re welcome, glad I could help!