First, the cats should be allowed to approach the screen door and encouraged to play with each other's paws at the under the door. Then, a very small gap or slit can be made in the cardboard so that they can barely see each other. The play under the door should be allowed for several days. Generally, cats do not redirect aggression unless they are touched or closely approached by another animal or person. If a cat is in an aggressive state or mood, it is dangerous for an owner to approach it, touch it. or try to pick it Up.
Cat bites are very serious to people, as well as to other cats.
One should not pick up or approach a cat that is highly aroused and aggressive. People should wait until after the cat has groomed itself, played. or eaten. Then, it usually is safe to approach the cat. In an emergency, during which an aroused aggressive cat must be moved, a very thick blanket might be used to catch the cat and then pick it up. In some communities, local humane officers, using special equipment, will help owners catch their cats.