Come spring, our two dozen birdhouses attract a large flock of swallows to the garden. I watch as they collect last season's remaining vines and other garden material to make their nests. Fall is the time to think of food for next year. But if rake you must, go right ahead. In most regions of the country, adult ladybugs overwinter under piles of garden debris and in other protected places, ready to emerge at the first sign of spring.
Snakes hide out under boards or in compost piles.
In the North, you can insulate a pile of rocks with an armload of leaves to provide a nice winter habitat. Reptiles and amphibians also hide in the nooks and crannies of loosely stacked brush piles, which you can make with fallen branches. Start with a two-foot layer of thick branches, and add a few more feet of thinner branches. In colder climates, top it off with a layer of evergreen branches. Birds and hibernating butterflies will duck in and find winter shelter there.