I've got 2 9 month old kittens who I let out during the day when I am at home and they regularly hop over the wall into the neighbours garden and beyond. 90% of the time they come back within a minute or so of being called, but tonight I've called and called (and walked round the block a few times) and one of them hasn't come home.
We have a cat flap but he doesn't know how to use it. We are in the city so I don't feel comfortable leaving the back door open all night.
What do I do?!