This looks just like a picture from our house. We have a similar picnic table and used to see possums out on our deck. They lived under our deck and we were worried about damage from their burrowing. We borrowed a trap, caught one, let it out in a nice place in the country, caught another and let it out in the same place. The trap was a wire box with a pedal at the far end. Hand food from a string over the pedal, the creature steps on the pedal, closes the door and traps it without hurting it.