Strange encounter

This morning I noticed that something had been digging in the mortar at the foot of the wall in the room I'm renovating and that an olive was inside the depression (oh dear where did the mice get in?!) .Having picked out the olive I discovered what I thought was another one in behind the first one.... which on closer examination was revealed to be this mini rhinoceros.......?! Is it a dung beetle? Did it mistake an olive for a ball of dung? Or did it want to go down a hole with an olive?