For each video, consider whether the organisms involved benefit (+), are harmed (-), or neither (0). Use your notes (or even better, your memory) to decide what type of relationship is shown.
A lion attacks and kills cheetahs: http://www.youtube.com/watch?v=8-wvA7fmUJ4
Pine beetles in the Rockies destroy trees: http://www.youtube.com/watch?v=yo69NtUMXBY
A barracuda gets his mouth cleaned: http://www.youtube.com/watch?v=TOC2Qc2Qedw
Bees pollinate almond trees in California: http://www.youtube.com/watch?v=EpdS4S4CQWs
