We have 2 cats who are just over 1 year old. One is very adventurous and uses the cat flap with no problem. The other has never used the cat flap and does not respond to any attempts we make to encourage him, including treats, leaving him outside and not opening the door - even when he's desperate to go outside and join his brother chasing birds in the garden he won't go through the cat flap.
We think this is because the day we got the cat flap installed, he had a bad experience - he was outside and a chair nearly fell on him. He bolted for the cat flap but it didn't open! It is meant to be activated by a chip, but he moved so fast that the flap didn't react in time. Our poor cat bashed his head hard against the closed flap and then ran off. If you even take him near the cat flap now, he struggles to get away..
I really want him to get outside so we can stop keeping the cat litter tray inside.. any tips would be gratefully received!