Maintaining a feral cat colony (in which all the kitties are sterilized and vaccinated against rabies of course) is so hip that New York City architects are getting their grove on designing housing for these cats! Most colony caretakers I know utilize the old plastic storage tub from Fred Myer with a doorway cut into it with a jigsaw and the sharp edges covered with electrical or duct tape. Straw, wool sweaters or fleece make good insulation. Or they find Styrofoam shipping crates on Craigslist and easily cut doorways into those. Pretty much any box made of waterproof material that you can cut at least one door into (two is ideal if it's large enough) will work. But for caretakers who want to unleash their creativity, here are some cool cat cubby ideas.