We have seven cats of our own and two fostered - they all have the run of the house and garden.
However, they are not welcome in my railway room - a separate brick built structure at the end of the garden - centrally heated for the winter and air-conditioned for the summer. However, there are times when I would like to work in there with just windows/doors open and the HVAC off - would one of those electronic/sconic devices work placed just inside the door ?
Your thoughts would be most welcome.