A gift from nature

So just before, my sister and I were listening to some banging noise that sounded from upstairs.  She thought it was a burglar, I however didn't really care that much after all I had locked all the doors and I think I would have heard glass breaking.  Anyway, so I humoured her, even taking a 'weapon' (hairspray) up with me just in case.

However, it was not a burglar.

It was my aunt's cat Dave.  He had brought a present for my sister; a nice fat mouse and was proceeding to take it up stairs to her bedroom (as her door was open). 

He looked really pleased with himself. 

My sister however did not.

Naturally I did the correct thing, got a couple of bags picked up the dead rodent with the bags and proceeded to throw it in the trash. 

My sister is disturbed by it.  All I can think of is; where the devil is my rodent present?