We had the same problems with out cats. we used a heavy box or something to cover up the cat flap as well as locking the catflap, we found that the cats wouod settle down if they couldnt see outside the flap as they could see they couldnt get out so didnt bother trying. They will get use to it. keeping going in time they will settle down, just keep at it and get them in the same time if possible. get them int a routine. our cats have got use to coming in they automatically come in at 10 ish most nights.
in reply to felix
We had the same problems with out cats. we used a heavy box or something to cover up the cat flap as well as locking the catflap, we found that the cats wouod settle down if they couldnt see outside the flap as they could see they couldnt get out so didnt bother trying. They will get use to it. keeping going in time they will settle down, just keep at it and get them in the same time if possible. get them int a routine. our cats have got use to coming in they automatically come in at 10 ish most nights.