Long Is the Journey, Short Is the Sojourn — Stephen Donald Huff

A marauding legion of starving aliens arrive on Earth for a brief but terrifying raid on the planet. For a few unbelievably deadly days they will raid humankind to fill their larder before they can continue on their indeterminate journey. Though the invaders are impervious to most human defenses, one man finds safety with a household pet! They are many and they are hungry. Human beings are defenseless. You never needed a cat so badly!