Ok, now I know that the movie I'm thinking of is NOT ghoulies, gremlins, or critters. But its along the same lines as those movies.
Its about these little creatures that go around terrorizing or killing people... they're not hairy or furry... I guess its like scaley skin or something... but they're reallllly little, and if you try killing them by smashing them I believe they multiply (kinda like gremlins and water)
And there is a scene where a guy is walking, I think maybe in a cave or abandoned mine and he has all kinds of hairy spiders all over his back.

That's all I can remember for now. I hope this sounds familiar to someone on here.

:D

I think that maybe this is the one you're looking for?.

Munchies (1987)

Hope that helped

OMG THAT WAS TOTALLY IT!! Wow, your good. Lol.

THANK YOU!!

:D glad I could help