Ark Workshop Outdoor Cat House Purchase the shelter

Outdoor cat shelter that someone built and it's so easy to build
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As far as the outdoor house & Mama's hesitancy, you might try a couple of things. The house might smell "too new." Smell is an important factor in cats. If you could put a cloth with her scent inside the house, it might make it more acceptable to her. I'd recommend (if Mama will let you pet her) - after petting Mama for a moment or so, take the cloth you want to place in her cathouse and rub it along the sides of her face & along her body. Her scent will rub off on the cloth. If you ever watched cats "scenting" a tree or other object, they will rub the side of their face along the object. There are scent glands along the side of a cat's face. (Since you do NOT want her to pee in her house, getting her scent any other way is not acceptable at this time.)
The best cat houses for feral cats and outside cat house for outdoor cats, feral cats, and toy dogs. | UnderCover Pet Houses.
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There are many homeless cats- some are feral cats, and some are abandoned pet cats. Whether feral or tame, abandoned pets, cats living outdoors need a warm, dry, windproof shelter. Make sure the opening is too small for a dog or coyote to fit in. All outside shelters should be off the ground several inches to keep the inside dry after rains have created puddles or to prevent a cat from getting blocked in by a heavy snowfall overnight (for regions that get snow). Quality Western red cedar wooden outdoor cat pet house with home insulation or heated option plus heated cat bed for one or multiple outside cats.
Photo provided by FlickrAlley Cat Advocates: building shelter for outside or feral cats for protection from cold
Photo provided by FlickrFeral Cat Shelter Options- instructions to make or purchase outdoor shelters for
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For those of you with cats who go outside, you may want to consider an outdoor cat house especially if your cat isn’t able to access shelter. There are other options such as pet doors, but you want to be sure you keep your cat safe.