3 Films I Need Help With

I have 3 films I remember from childhood and they were all horrors......I THINK!

The first film involved a group of people, plain people for example a fisherman etc and these alien things that looked like....pancakes (dont laugh) would fly onto their faces and I think the outcome resulted in them dying but im not sure. (p.s Im not on about ALIEN)

The second film involves another group of people but in the jungle and a group of ants would go around killing each one of the group, one of the scenes I remember is the ants going across a stream on leaves.

Finally the third film was set in England (I think) and the very first scene involved a person uncovering dead peoples faces under the snow. It turned out some kind of alien thing was under the snow in some kind of base.

If anyone remembers any one of these please let me know!