After too many close calls with prior cats and since we have 3 bird feeders out back and do not want to invite them to their deaths, our cats are indoor cats even though they like to go outside. The way we solved this is to buy them harnesses and attach them to long ropes or cables to let them go out. We only do this when we are in the backyard with them (wouldn't want them going after birds or chipmunks or being attacked and unable to get away). They seem quite content with this arrangement.