I use a leash for my cat. She's escaped through an open door before when it was dark outside, and she took off. We live in an area with woods directly behind us and a busy road in front of us. It's not exactly the best place for an indoor cat to wander around in! I put her leash on when I go in the backyard to relax or garden. She sits and waits by the door for her leash, and when it's on she scurries outside and usually plops down in a patch of sunlight and takes a nap. Sometimes I'll walk her up and down the sidewalk in front of the house, but she usually ventures into the grass and starts eating it! People laugh when they see a cat on the leash, but it's the best option for her. Chasing her around in the woods at 2 a.m. was not fun!