Frog-as-pred not triggering

After downloading 0.1.6, I was curious about the frog. Have tried Slugcat-as-prey with food pips a lot, without food pips (Slugcat cringes to show that Frog is attempting to draw food pips), and even whipping the poor little frog around with mouse drag to try a high velocity accidental-vore. Cannot trigger frog-as-pred.

As an aside, are leeches in the pipeline anywhere? They grow as they attack but I think that's from Rotundworld, but they're definitely eager to eat someone... annoyingly sometimes.