Does 'Survivor' Have Jungle Fever?

A Contestant Starts To Scare Others With Unusual Behavior

(CBS)  "Survivor" returns to its Thursday night time slot this week, and the cast gets dirty in the jungle.

Matthew Von Ertfelda, the restaurant designer, is starting to give his fellow "Survivor" contestants the creeps because it seems that he is fixated with sharpening machetes. Is he catching jungle fever?

To some, "Survivor: The Amazon" has a lot more sexual tension then previous seasons, and that doesn't please everyone.

As Heidi Strobel, the teacher, and Jenna Morasca, the swimsuit model, bathe each other, Rob Cesternino voices his concern that they are using their sexuality to manipulate their fellow "Survivor" contestants.

Also, one "Survivor" contestant embarks on a highly strategic relationship with a member of the opposite sex. Will it work? Fans will have to watch the next "Survivor: The Amazon" to find out.