[Charliesmum6]

Hi everyone, any ideas on if these tricks work on an older cat?
Charlie is 9 (we think) and we're fairly sure has never had a catflap, we got one installed and he's fine using it as long as it's ducttapped open...but today I've come downstairs to find another cat eating his food! Turns out for a large cat (siberian) he's a wuss and was too afraid to do anything.
The problem is that he doesn't understand how to push against anything and doesn't use his paws to investigate things so he won't paw at the door or anything. He also cannot understand that he can push doors open.
Any ideas? He's been really weird the last week and I think we've found out why if this intruder is coming in daily
Thanks