My Bp tends to eat it tail first also. He has done it quite a few times and I know although many don't recommend them eating it backwards. I don't believe it does much harm. Just keep a close eye on the Bp when he eats it backwards to make sure he gets it down alright.

I'm not quite sure how they know to got towards the nose/head of the mouse. Sometimes mine tries to eat the mouse horizontally and I'll just walk away knowing that hes gnna have to eventually realize he cant eat it that way.

Whether he eats it head or tail first, as long as he gets it down alright and eats, I am a happy camper :]