Just a little tip for anyone who wants to know. Unlike zombies, the bloodsuckers can get you when hiding in large trees or bushes. Now you might think that's unfair but it really does make things interesting and a little more difficult. There is one thing I have noticed the Bloodsuckers can't do though. and that's climb ladders. I killed 3 with nothing but a G17 (headshots work yippie!) whilst up a deer stand. The only real threat was the zombies climbing the ladder. Hope this helps :)