I think intelligence is the correct word. Why not?
It's also seems odd to call it "baffling" when they 100% understand how it works!
1) It's a poorly defined word that means different things to different people
2) The word "mechanism" perfectly describes what it is
At the end of the day it's just using the detection of food, to switch from "tumble" (try a random direction to find food) to "run" (assume we're near, or in, a patch of food, and move forward to consume more).
But also we're in a context where acknowledging the intelligence of other life forms is pretty radical so distinguishing them as 'lesser' than human would be precisely opposite of the point. The baseline world view is that human intelligence is magically different than other animal intelligences.