For the past 2-3 months, one of my large female leopards has been exhibiting nest digging behavior - but only on top of a large concrete slab in my yard. Every day she spends the afternoon frantically grinding her hind legs into the concrete after urinating on the spot. She does this for hours. Her rear claws have been worn down to nubs now and I'm starting to regard it as a neurosis rather than a misguided nesting attempt.

Anyone every hear of this, or have any advice ?