Bob Eager wrote:
On Sat, 19 Jan 2008 23:04:26 UTC, "Roger Mills"
wrote:

Alternatively, could you not just put a simple bar across, near the
bottom, to stop the flap opening? This could be pivoted one end so
as to swing out of the way when necessary, with the other end pushed
into a simple bracket when you want to keep the flap shut - or maybe
two, a parking bracket and an operating bracket.

Our cat would have taken the hinges out in that situation.

Alternatively yet again, doing a quick Google for 'cat flap'
suggests that there are locking cat flaps - which may fit the bill

I suspect he's already tried those.

Yup - as suggested by Bob, the little rat breaks through...

I wonder about a simple flap, same size as the cat flap, hinged
horizontally about the flap. Two turn buttons or similar, one to hold
it up out of the way, and one (perhaps a bit more complex since cats
can be very dextrous) holding it shut over the cat flap.

Yeah, that's the final solution - a hinged 12" x 12" door which closes over
the whole area and latches with a metal fitting. Trouble is, SWMBO doesn't
want that hanging off the inside of the door, so trying for more discreet
options first.

Thanks both!