Garage Protection with Pets

[Foo Bar <nospam@xxxxxxxxxx>]

Another newbie question here.

House is a combo wired/wireless with an Ademco 20P panel. I have a
problem protecting the attached 2 car garage. The main garage door, the
door to the house and the back door are mag contact protected. The
problem is that we have cats and sometimes want to bypass the back door
to let them go in/out while away for a short time. Thus I need some sort
of "space" protection to pick up someone who may enter via the
bypassed/open back door. I first tried an Aurora PIR mounted just below
the open rafters. Unfortunately, with small cats, if they climb into the
rafters, they are close (and hot) enough to simulate a 40lb critter. I
pulled the Ademco and replaced it with a microwave/PIR combo unit. Much
better but still managed to false once. I guess I could be very careful
in locating the PIR and masking out the usual location that the cats
might be in, but I am hoping one of the pros can suggest a more
cat-proof volume protection sensor.

         -Bill-