Any tips on catflap training? We got it fitted in the front door (in fact we got a new bloody door complete with catflap) and they have only used it sporadically to go out. This is them at the back door wanting in rather than let themselves in! How can we get them to use it? Wanted them proficient as we go on holiday at the weekend and have a cat sitter booked to come twice a day. Didn't want them to be trapped in for 2 weeks but may have no choice 