Back in the dorm, Liam and Sara confirm that the exploding toilet is still a mystery for the ages.
Emergency Backup David's back in the morgue and processing Kevin's body when Nicky bursts in hooting, "Crop circles? Come on, Super Dave, wasn't the alien autopsy embarrassing enough?" Wow, it's a rare day when Nicky can bust someone's chops at work. Usually he's the forensic piñata. Emergency Backup David replies, "Given the circumstances, alien was not an unreasonable conclusion at the time." Nicky snickers, "You need to get a girlfriend." "I'm engaged," Emergency Backup David snaps. Warrick's got a look like, And what does that have to do with getting a girlfriend? Then we get down to transmitting information: there's grass stains on Kevin's knees, and his tighty-whiteys were soaked in urine; it's unclear if that's pre- or post-mortem.
Just then, a big, flat white worm comes poking out of Kevin's mouth. Warrick yelps, "Ohhh! That's ALIEN! What is this?" Emergency Backup David grabs a camera and says, "I've got to document this." Nicky gets to bring the science -- or so he thinks -- with, "Hang on. We've got ourselves a tapeworm, gentlemen. This guy's been eating meat or fish infected with tapeworm cyst." As the TMIcam shows the cyst settling in a stomach, Warrick adds, "And that cyst grows up to be a nice, fat tapeworm that attaches itself to the intestinal wall to suck out all your nutrients." Nicky concludes, "Since this guy's dead, the tapeworm needed to find a new host." And that's when I said, "Really?"
My first question upon viewing this was, "How does the tapeworm know when a host is dead?" They're not extraordinarily complicated creatures. The guy was probably infected with one of two tapeworms: the beef tapeworm (Taenia saginata) or the pork tapeworm (Taenia solia). Both are pretty basic animals, with two outstanding body parts: the scolex, which attaches to the gut and becomes the primary means by which the worm ingests (our) food; and the proglottid, which is a flat segment containing both male and female organs. The tapeworm will continue to add proglottids throughout its life -- beef tapeworms can have 1000 of 'em -- and the terminal proglottid's the one that performs a reproductive function: it breaks off the worm, passes out of the human host, and releases eggs, thus beginning a new lifecycle.