I think I have a phantom, nocturnal critter in the house. Twice I have found a few spots of flour on a carpet that does not connect to my kitchen, but I did have a bowl with flour on my kitchen island. Then I heard (only one night) what I assumed was a very noisy mouse crunching on a piece of dog food in a junky corner of my bedroom after turning off the lights. This morning I found a piece of cookie on a foot stool and a mouse trap I had baited with peanut butter, but accidentally had sprung, dragged from my bedroom into the living room with the peanut butter gone (another remains baited and unsprung behind a door with room for a mouse to get to but not my chihuahua). The dogs had been in their kennels. The cookies were on top of a 4 1/2 foot entertainment center in a cellophane pack. The only feces I have seen was a light brown smudge on the carpet I assumed came from a dog. I was wondering if a squirrel would become nocturnal inside, and would appreciate any other ideas. Please help!