Hes just discovered the cat flap is working, so he went out into the dark night. The thing is that now both of my cats are inoculated they can go out. But there is the abandoned cat outside and he’s twice my boy cats size and even bigger than the girl cat.

So boy went out through the flap, but couldn’t get back in because the abandoned one was hanging round for food. Solution. Put a tray of cat food further up the yard to distract the abandoned one, then call boy cat in. Finally lock the cat flap for the night…. Result he can’t get out! Will open it again in the morning.