Well, so far, so good. These spikes do appear to work. Obviously, it's a bit difficult to 'prove a negative' but so far I have not had any more furry visitors.
I did notice one cat climbing up towards my wall, putting one paw gingerly up towards the area that has had the spikes fitted and then quickly deciding that perhaps it wasn't such a good idea. Another local moggy just looked disgusted and stalked off.
I think that the secret to successful use of these spikes is in the positioning. If you can, fit them in an area where the animal is going to have to jump up, then they will work very effectively. However, if you fit them somewhere where the animal may simply walk, albeit carefully, in, on and around them, then they will not be so effective.
The strips each have three rows of off-set spikes. They are fairly easy to fold, if you want to fit them around the top of a fence. Equally, they are fairly easy to split into 2 or 3 strips by the careful use of something like a
Stanley Knife. The spikes are made of very solid and hard plastic and are considerably more robust than I thought they would be, which is good.
I am also using a
PestBye Battery Operated Cat Repeller and that, with the spikes, has resulted in a cat-free or, more to the point, cat poo free back yard.
So - recommended, but a little bit of planning may be necessary in order to make the most effective use of them.