My barn cats have decided that coming through the doggie door and into the house is a wonderful experience! My dogs love cats, so they are no help. I have tried those electric sound makers made especially for cats - they quickly discovered that if they ran past it fast enough it only hurt their ears for a milli-second and the reward was well worth the trouble. I have tried sprays that are supposed to keep them away. I have blocked the doggie door for several days at a time hoping they would loose the habit. Until now, I have not been home to reinforce any behavior modification on a regular basis. I love them all dearly, however, it's no fun coming home to 10 barn cats in the house! Please help!!