On Sun, 12 Aug 2012 05:17:36 -0700 (PDT), Gas Bag
wrote:

A friend of mine has one of these fences that's about 178cm (5'10")
tall:

http://stratco.com.au/products/fenci..._neighbour.asp

She wants to stop her cats getting out, and other cats getting in. I
know full well that there are numerous commercially available products
that will stop cats (along with other animals) climbing fences. I'm
sure they do work, but they're all fairly pricey, particularly if
attempting to cover a significant length of fencing. I'm now thinking
about trying a home-rigged set up. I'm considering getting a whole
heap of empty 2 Litre plastic softdrink bottles (Soda bottles to any
USA readers), then cutting off the base and neck of the bottles, then
cutting them lengthwise, then siliconing them to the tops of the fence
so the sides of the bottles "curve downwards" from the top of the
fence. I'm thinking this curved plastic will be too smooth and
slippery for a cat to get any grip with it's claws. I have no problem
with spending some time getting this to work, but I want to keep the
cost down, so spending lots of $$$ isn't happening. Again, I am aware
of many commercially available products.

I was wondering if anyone has attempted anything like this, and if
they can offer any advice. Thanks.

To any cat "lovers" out there, my friend isn't getting rid of her
cats, nor is she trapping/baiting any of the cats in her suburb.

I have four cats and an 18' by 50' backyard with a 4' chain link
fence. I extended the fence with 4' of some fencing from Home Despot
and have the top foot bend in at a 45 degree angle. It does a
reasonably good job of keeping my cats in the yard but does not stop
other critters from entering. I leave a door open when my cats aren't
there so the other critters can get out.

We have possums and raccoons in the neighborhood even though this is
New York City. Raccons are a pain in the ass but possums are pretty
cool. And of course we have feral cats but we've neutered most of them
and we sort of try to take care of them as much as we can. They have
nice styrofoam houses lined with straw for the winter and are well
fed.

Once in a while some critter actually forces its way out through the
fencing, leaving a hole that my cats can use. That just happened last
week; one of the bolder ones was trying to get at a squirrel in a tree
next door and was halfway through a small hole when I grabbed him.

It works pretty well though, but over time almost any fence will
develop a weakness. I use the Loc8tor for that - each of my cats has a
collar with a Loc8tor tag and I can track them for a short distance.
One cat still has out priviliges (I took him off the street in front
of my house and he likes to visit his old friends once in a while). I
can track him pretty well with the Loc8tor so I know that it's
effective enough for the job.

There is always a risk in letting cats out of the house though. I know
many folks think that it's cruel to keep cats inside all the time, and
they have a point. My cats love going into the yard. But I keep it as
safe as possible yet there is always some risk.

One of my neighbors had six cats and one was allowed to roam the
neighborhood since he wasn't happy otherwise. It was sort of cute,
he'd be sitting on the air conditioner waiting to be let in most
mornings as I'm heading off to work. He didn't come home just three
days ago, and when we were asking around we found out that a black cat
had been hit by a car a few days ago. So he won't be sitting on the
A/C anymore.

Cats that are outside will die sooner or later (not very insightful I
know since we all will die). But the odds of something bad happening
go up rather quickly once they are out of the house. The fencing makes
it a tolerable risk.