What's for Lunch?

The string theorist Michio Kaku was asked recently to speculate about what alien civilizations might look like, how they might behave.  He answered that very likely at some point in their evolution they killed, and ate what they killed.  How so?  According to Kaku, predatory behavior correlates with intelligence.  The fox is smarter than the bunny.  The bunny need only learn to run away, as fast as it can.  But the fox must learn to strategize the hunt.  Since we know that the aliens must be very smart to get here, they must also have a history of predation.

(Is this true as a general proposition?  Is the alligator smarter than the faun that it pulls beneath the water and drowns?)

The subtext of the remark is clear.