A seemingly regular aquarium, populated with dwarf lanternsharks and/or any other carnivorous fish (piranha?) that will eat mammals if they are made available to it. The top of the aquarium is slotted like a kitchen spoon, with an oscillating fan atop it to blow the aquatic scents far and wide. The slotted lid, accessible to even the craftiest feline only by leaping atop the aquarium, is in fact a trapdoor held shut with a 5-pound-test spring.
Placed in an open window to serve as both decoration and lawn/garden pest control, it is no more cruel to cats than Venus's Flytraps are to flies. Don't want to see your own cat end up as fishfood? I recommend keeping your cat out of the yards of such homeowners, and in return we will gladly continue to control our own pets thusly.
If it wasn't so bloody impossible to catproof a lawn, such measures wouldn't be necessary. Here in Spokane, Washington, USA, the maximum legal height for a front-yard fence or wall is 4 feet (6 feet for the backyard) and topping it with barbed wire, nails or broken glass to keep small animals from landing atop the wall or fence is illegal.
A 4 foot fence is more than adequate for keeping stray dogs out (and usually adequate for keeping them in, too). They actually respect well-defined boundaries.-- 21 Quest, Dec 16 2011 … and there was Much Rejoicing.
[+]-- 8th of 7, Dec 16 2011 Excellent idea, [21]! I shall recommend this to our city fathers for use as municipal decorations on every street corner... [+]-- Grogster, Dec 16 2011 You're welcome. [+]-- Alterother, Dec 16 2011 //maximum legal height for a front-yard fence or wall is 4 feet//
haha...you need a haha-- not_morrison_rm, Dec 16 2011 I'm confused.
You have a yard with dogs in it, and you worry about cats on your lawn?tsk tsk-- 2 fries shy of a happy meal, Dec 16 2011 I don't leave my dogs out at all day, 2 fries. Most of the time, they're in the house with me. And a haha would be awesome, but they can be expensive, especially one deep enough and with a smooth enough wall to keep a cat out.-- 21 Quest, Dec 16 2011 // especially one deep enough and with a smooth enough wall to keep a cat out. //
I rather thought the point of a haha was that things stay _in_ it. Terminally, even.-- Alterother, Dec 16 2011 Well either way, it wouldn't keep a cat in or out.-- 21 Quest, Dec 16 2011 Picket fences and some block walls are often topped with blunt pyramidal forms in order to make their use by cats, skateboarders, and other pests more difficult.-- ye_river_xiv, Dec 16 2011 what a strange category-- po, Dec 17 2011 What's strange about it? Am I not allowed to be amused by the success of my adaptation of nature's plan?-- 21 Quest, Dec 18 2011 I think it was intended as being entertainment for the cat!-- po, Dec 18 2011 // Be prepared for your Assisted Curiosity Programme to backfire as your property is surrounded by hundreds of staring cats//
This is what is referred to as a target-rich environment. Backfire you say? I call that success.-- 21 Quest, Dec 18 2011 random, halfbakery