David - in case she did sneak outside, can your vet or SPCA lend you a live trap? Put some nice stinky tuna in it, and hopefully Nikki will get in!

If you have a porch or some space underneath your house, put it there. She would be hiding under there, I would guess.

You can also try going out after dark, calling her very gently, and maybe gently shaking the box of food.

Also - do your neighbours have any garages or sheds where she might have hid? Maybe they went away for the weekend...leave a note on their door.

Dearest Nikki - please come home. Your dad is worried!