Backyard Genius: Snap - a sheep is caught and the dog is warm

Tony Prentice's dog Mouse models the thermal dog kennel, which has a door and insulated walls. Pictures / Simon Baker

Mention "Super Crook" to your average townie and you'll likely trigger an armed offenders alert.

But not on the farm. Super Crooks are welcome there. Certainly the ones that Tony Prentice has created.

His Super Crooks are designed for safe handling, not handling safes. All they snatch are sheep, goats and pigs.

"We've sold hundreds of those," says their inventor proudly. "They're bloody good."

A feature of Tony's crook is the catch or lug at its head - not unlike the clip that keeps a key ring on your belt.

With the catch, "you can grab a sheep by the front leg, the back leg, and it's always like a handcuff".

The crook is also "good for electric fences. It's insulated, so you can hold the wire down." .

All good news for cockies, as Tony well knows. Although he's living in town now, he spent 45 years farming "lovely terraced country" at Claverley, just south of Kaikoura in the South Island.

That's where he developed the Super Crook.

"It got an award at the field days about 20 years ago. But we've improved them since. My daughter sells them now. They go through the stock firms."

Tony is hoping his latest invention will also be part of the Wrightson stuff - and the others too, of course. But that hasn't happened yet.

Partly because the 80-year-old "got buggered up a bit" when he was "run over by a car in front of the unit. But I'm coming right. I'm getting back into it".

That's what he wants dogs to do too. Forget every dog having its day, Tony thinks they should have a night - and a comfortable one, at that.

"Dogs love heat." he says. "If it comes up cold they go to the warmest place around." Which often isn't their kennel.

"I saw some dogs in dreadful conditions when I was kicking round the High Country," Tony recalls. "People would buy these expensive kennels. But the door was always open. And facing the wind."

He's solved that problem with a swinging, two-way polycarbonate door that keeps the warmth where it's meant to be - inside his plastic, circular, double walled Thermo Kennel.

If it looks like a 44-gallon drum, it's because that was his inspiration.

When their petrol came in drums, farmers would often turn the empties into kennels and Tony realised the shape was perfect for his purpose.

"I've been working on it for the last two years," he explains.

A major problem was finding materials "dogs couldn't chew and are impervious to all the bugs and everything else. I tried everything as an insulator, y'know".

Eventually, he chose polystyrene as the insulation to fill the cavity between the Thermo Kennel's walls. It does for dogs what blankets do for people.

"Blankets don't give you any heat. They just act as insulators. You provide the heat. It's the same here. The dog provides the heat, the kennel just insulates it. It's more of a nest than a kennel."

Waterproof, indestructible, relocatable and snug - a shivering sheepdog's Shangri-la.

"The sheepdog is the only animal that's been bred for its brains," says Tony.

He thinks they deserve the best and he's determined they get it. "I was keen as mustard till the accident, then I ran out of guts. But next year I'll push it along. Yes, we'll get into it then."