Question
QUESTION: We have an open porch/deck, with windows on 2 sides.  The problem we have is the strays spray the window every night!  I clean the window with those antibacterial wipes and windex, but that doesnt seem to be a deterrent.  I have looked @ the website, and I couldnt figure out what to use to stop this, as it is on a window!!  Please help!

ANSWER: I don't know where you live as it may be too cold to try one of the techniques. Unfortunately, there are no magic solutions.

I would consider using the scarecrow motion activated sprinkler or something called a scat mat. The latter shocks animals that step on it. Lay it down underneath the affected window.  You could try fencing to keep the cat away from that spot in the hopes it will break the pattern.

Finally, push for leash laws on cats. Although the cat lobby is extremely powerful and vocal, the fact is free ranging cats are a menace to the environment and a threat to people through disease. More details on http://icwdm.org
Your problems with free-ranging cats are not unique. It is sad how we have allowed the cat lobby to dominate and trump property rights.

---------- FOLLOW-UP ----------

QUESTION: Sorry, I didnt give the location.  We are in Maine.  It is very cold this year.  I was hoping for an idea more along the lines of a spray or something that I could use on the exterior of teh porch/window.  Any ideas??  If not, thanks for the help!

Answer
Short of anything listed on our site, which you said you already checked,
http://www.icwdm.org/handbook/carnivor/FeralHouseCat.asp  no. I have very little confidence in repellents as explained on http://www.icwdm.org/ControlMethods/repellents.asp   

It is biologically speaking essentially impossible to repel a carnivore in most situations. Solutions often lie in control, guard animals, or barriers.