Have a look he-

http://www.pyronix.co.uk/english/pro.../petimmune.htm

and a desciption of how a person crawling along the floor is
differentiated from a pet:-


http://www.pyronix.co.uk/english/pro...mmune_spec.htm

Yes, agreed and all very good providing your cat doesn't jump onto a worktop
within range of the PIR! These new technology PIR's are brilliant but are
far from fool proof. Expect false alarms and if you don't get any it'll be a
bonus! In any event use a dual tec unit in a kitchen as I mentioned earlier
and as illustrated on the above pyronix site.