We have a cat door through the screening, Hetty. I can lock it, but then the cat wakes me up wanting to get out . . She also has a door into the house that is operated by her microchip, so the raccoon can't get into the house, but the cat puts up a fuss when raccoons get into the cage. He's really only after the water in the pool, since it's been so dry but there is lots of other water around our yard including the water garden that would be easier for him to get to.
