Right now my players are in a forest tracking down some giant rat people, I got the idea from skaven. As of right now I have only presented the rat people as a combat encounter. Does any one have any other ideas on how I could let them learn more about them or let them see them without them being attacked? Also they have been tracking them for quite sometime and I was also wondering if anybody knew of any other forest creatures they could get attacked by and lead them off on a mini adventure to keep them exited and moving?

That all depends on the kind of environment your in. I know you said forest, but there's a difference between a forest on Dusk and a forest on some random agri-world. If your going to use giant rats though, why not put in their predator? A big.....very extremely not small cat. Another question would be how many players you have and their ranks.

I don´t want to be a party pooper, but since RoBros inital question was from AUGUST, it do not think that the group is still in that forest.

or is it, RoBro?

If it doesn't apply now, if they do a return adventure it could apply in the future. I figure any input could at least serve as inspiration for future campaigns if nothing else. But for all we know, they're still stuck in that forest full of giant rats.