I mean, stagmoles might just taste very bad. That usually stops most cats?
Maybe bearyenas hunt for sport. Or not... with stealing, their eyesight during daytime could just be really bad. I guess it's not unikely that somewhere between their and nichelings' common ancestor, that they originally evolved in different, specialised places. Then wandered as things driven to wander do. But they don't exactly starve, either. That might just make it hard to adapt. Or they're not competitive enough during daytime to make the step.