How to Reduce the Unwanted Behavior
Neuter. If cats aren’t neutered or spayed, obviously that step should top the list. Don’t make the mistake of thinking you just have to neuter the males without spaying females. It’s not just about eliminating the risk of pregnancy, it’s about reducing stress and creating an environment for healthy behavior.
Never punish. Never punish a cat for exhibiting mounting behavior because it’ll only elevate stress levels. A cat who is attempting to mount due to social stress in the environment will only feel even more anxiety if physically or verbally punished.
Increase vertical territory. Increase your cat’s sense of territorial security by expanding vertical territory. This can be done by way of cat trees, window perches, elevated walkways and elevated beds. Vertical territory allows the cats to more peacefully establish and maintain status. Claiming a top elevated spot is an important factor in status.
Provide scratching posts. Scratching serves many purposes for a cat and one them is to mark territory. This can also help in communicating status. It also serves as a displacement behavior to help relieve stress.
Resource availability. Provide multiple resources in multiple locations to prevent competition and jockeying for prime position. This means more than one feeding station, more litter boxes than cats, and plenty of napping, hiding and personal space options.
Introduce new cats carefully. The addition of a new cat may trigger the behavior. To reduce the chances of this, do a gradual, positive new cat introduction.
Increase the fun factor. Increase physical and mental activity to give your cat beneficial outlets for his energy. Engage in interactive play sessions at least twice a day.
Other ways to occupy your cat’s time in a fun way is to set out puzzle feeders. This provides your cat with the opportunity to work for food rewards.
Work to improve relationships. In addition to the above suggestions, pay attention to the specific dynamics between cats so you can help them co-exist peacefully. This may just involve making environmental adjustments as mentioned above, or you may have to separate them and do a reintroduction.