My sister is moving into a new apartment, and is bringing her two cats ,zap and kiff, along. the problem is, she wants to be able to let them out onto the patio of the new place, without worrying about them running away. the patio has a fence four feet high all the way around it, and the upstairs tenants have a balcony above, so our original plan was to screen it in and make a screened in patio. unfortunately, the managers of the complex say that all of the patios must be the same, and screening it in would create a large aesthetic difference between the apartments. does anyone have any ideas about how to keep the cats from jumping over the fence without changing the look of the apartment?