Possible feeding habit of "Skeletal" figures....

After reading a brief description of what happens to one (or many) of the crew members 30 minutes into the movie, I wonder what method of attack do these "skeletal" figures use. Judging by the shape of the head and what looks like a proboscis of sorts (if that indeed is the full shape of the the head and not a helmet), it would seem the "feeding" habit would involve some sort of puncture and suction. The shape reminds me of the giant water bug (toe biters), who punctures, injects, dissolves and sucks out all the soft tissue inside an organism (very monstrous). This is oddly similar to the method used by the xenomorphs to attack (and feed?) except that they have a mouth at the end and tear down flesh instead of syphoning it. But anyway, just thinking about the water bug method of feeding and applying it to a monster-like creature who feeds on bigger organisms, gives me the creeps; Imagine a human or a dog or any big animal for that matter, being sucked from the inside out, leaving only loose skin and the shape of its skeleton....really creepy indeed.... If whatever becomes the xenomorph is shown in this movie, it should have some resemblance in behavior to what it will become, don't you think?