It Does not evolve by leveling up. Use a moon stone. You may want to raise the Nidorino to LV58 So it learns a One hit KO first, though.
With a moonstone :) ... But you should probably only evolve it when it already have learnt a good attack (horn drill)
With a moon stone.
With a moon stone
Dude you have 2 use a moon stone of the Nidorino.
Use a dam moonstone you dum bow
Shut the "beep" up use the "beeping" moon stone you "beep"
It doesn't evolve by leveling; you need to use a moonstone on it to let it evolve.