Hiya, I am sure someone out there can help, we have four cats, all lovely of course and all very friendly. To the extent that I am sure they are offering open invitations to all cats in the neighbourhood to ' come back to ours for some dinner' LOL Although they are not fighting and often will sit and watch our visitors eating!!!! However this is becoming a little tiresome and one of the four is a little nervous when the cat flap goes. We live in a rural area and our cats love being outside, especialy in the summer. The only thing we can think of to stop this 'open house' is to get a chipped cat flap, three of our four are already chipped by CPL so didn't know if anyone has advice on whether these work and what sort of procedure our fourth cat would have to go through to get chipped. Any advice welcome.