She sprays WD40 around the garden on bricks, walls and other hard
surfaces,
at regular intervals and claims that this keeps the cats away.

My wife has just smeared petroleum jelly all along the top of our boundary
wall. Probably has the same effect. The muddy paw and claw marks down the
wall are like something out of a "Tom and Jerry" cartoon :-))
--
MCC

So, is this a deterrant, or is it just a lubricant that makes it difficult
for
cats to walk along the tops of narrow surfaces such as fences?

In the first instance it is just a lubricant that makes it difficult for the
b****rs to get a grip, but having fallen off once or twice, I doubt they'll
want to come back too often, so it is ultimately a deterrent as well :-)

--
MCC

There are just two problems with this. Firstly it's no good if it's just a
lumbicant if you have nothing such as a fence to spray it onto, and secondly,
if the cats don't fall off, from what you've said, they won't be deterred,
which is exactly why I asked the question.

Dave.