“At a certain season of our life, we are accustomed to consider every spot as the possible site of a house.”
-Henry David Thoreau
Not so long ago, before we mastered wood, stone and iron, we sought refuge in caves, huts of mud and sticks, or slept under the stars. We weren’t so different from the animals. In some ways, we still aren’t.
How do animals know where to make their homes? Sometimes they take over the homes of others. Coyotes will readily move into and enlarge badger dens, for example. Sheltered from the elements, the same burrow can be used by many generations of different critters. This type of house-hunting is very much like our own. Most of us don’t have the opportunity to survey a large tract of land and select a particular site to build; we generally live someplace that was once someone else’s home, usually many others’, most of whom we’ll never know (and who never knew each other).
A burrow or den is the most common home for mammals. Like sculpture, constructing an underground home is an act of subtraction. This is suitable for creatures who lack opposable thumbs. Some animals manage to subtract quite a lot. According to National Geographic, an average groundhog, which weighs in at 8-10 pounds, moves over a ton of soil when digging its burrow, which may have over 40 feet of tunnels up to five feet underground, and a “well-developed” rabbit warren may be thousands of meters long. Nearly all burrows have more than one entrance to facilitate escape (as do our homes, at least since the advent of fire codes).
Living underground is especially sensible in the hottest and coldest climates due to the ground’s temperature-regulating effects. Humans made use of this property until quite recently as an important way to preserve food; no home was complete without a root cellar. Today, geothermal heating and cooling systems operate on the same principle.
It is possible for humans to live almost entirely underground. “While earth-sheltered housing is not common, it has been around for a while,” notes offthegridliving.com. “During the energy crisis of the 1970s, people became increasingly interested in finding ways to reduce their consumption of fossil fuel, and energy-efficient forms of architectural design and construction began to draw a lot of attention.”
The results were mixed. After energy prices fell, underground construction was no longer cost-effective. Keeping moisture out isn’t cheap. Extensive waterproofing is needed on all surfaces that will touch earth (the soil above the ceiling is a particular concern). Tolkien spoke to this when he described what Bilbo’s home wasn’t. “Not a nasty, dirty, wet hole, filled with the ends of worms and an oozy smell, nor yet a dry, bare, sandy hole with nothing in it to sit down on or to eat: it was a hobbit-hole, and that means comfort.” (How the Hobbits managed to regulate the humidity in their holes was not discussed.)
Animal burrows are far from water-tight, but they do tend to select sites in loam rather than clay, and on the sides of hills; both choices facilitate drainage and make excavation easier. Animal burrows also tend to face south for warmth, unless prevailing winds or some other landscape-specific feature rule it out. Precisely the same type of soil, site and orientation are suggested for earthen homes for humans.
In our part of the world, there aren’t many animal-built structures that sit on the ground. So we move next to the trees. Squirrels will make their homes in tree cavities, but they also build nests called dreys, which are similar to bird nests, but enclosed, so they’re more like the kind of structure we’d build. Dreys are easy to spot when the leaves are off the trees, usually at the crook of two large branches, at least 30 feet up. C. Clairborne Ray wrote admirably of their haphazard look but complex build in The New York Times. “The squirrel begins by roughly weaving a platform of live green twigs. On top of this, soft, compressible materials like moss and damp leaves are added. Then an outer skeleton of twigs and vines is built around the insulated core, and finally, additional material fills in and strengthens the shell.” A hard skeleton, overlaid with other material to form a solid wall, with an insulated core— sound familiar?
The squirrel’s rodent cousin, the beaver, is second only to man in its ability to change a landscape. A lodge, built of mud and sticks and dutifully maintained year-round, can shelter up to 15-20 beavers, and contains one chamber for drying off and another for regular day-to-day life (kind of like a mudroom). And while squirrels build their nests among their avian predators and a burrow offers little defense against a tenacious predator that can also dig, a beaver lodge is about as safe as it gets; the layers of dried mud and sticks form a virtually impenetrable outer shell, and the entrance is accessible only through passageways hidden under murky water. It’s the closest thing to a medieval castle in the animal kingdom.
A major difference between us and the animals is the need for cover. Whether they’re prey, afraid of being eaten themselves, or predators, afraid of their young being preyed upon, most creatures pick secluded places to make their homes. That impulse is less common in us, but not unknown. Witness the non-descript and narrow stone driveways leading deep into dim woods you see here and there off Hudson Valley roads. How far back do they go? Who would want to live in a place like that? Standing outside such a portal is about as inviting for the would-be trespasser as the mouth of a wolverine’s den.
Still, for most of us, most of the time, there is no danger, and no need to be inconspicuous. Here is an exception: A soldier behind enemy lines, for whom, like a wild animal, being caught unawares could mean death. The Army’s survival manual offers the following acronym for shelter site selection: BLISS (Blend in with the surroundings; Low silhouette; Irregular shape; Small; Secluded location). A beast couldn’t have put it better.
Of course, there are differences between a campsite and a homestead, a temporary and permanent settlement. Like animals, we have our preferences, and like them, those preferences are contingent. Private property and the rule of law constrain the places we can settle; animals fight it out. (Though anyone familiar with small-town neighbor disputes knows territoriality is still alive and well in us.)
With them we share the need for food and water. For us, that usually means farming, which is more trial-and-error than instinct. How did we know where to try to make a go of it? We probably used one of the methods suggested in a 1971 article in Mother Earth News on “Selecting a Homestead Site.”:
Soil fertility can also be determined by observing plant growth. Fast growing weeds like giant horseweed or cockleburr indicate good soil conditions; red sorrel grows in poor acid soil. If the plant has a deep color the soil in which it grows is probably fertile. Tree limbs that extend upward and do not droop also indicate fertile soil. Walnut, cypress, whiteoak and cottonwood trees are all good soil indicators; blackjack and pine grow in poor soil.
The modern homesteader has the benefit of thousands of years of agricultural practice and hundreds of years of science. One example from the article mentioned above: The 1913 U.S. Department of Agriculture Yearbook reported that land sloping 5 degrees to the south in Idaho has the same solar climate as level land some 300 miles to the south in Utah.
Still, much is left to the whims of weather and pests. No wonder most religions have centered around pleas unto heaven for a good harvest; we just had to hope for the best. And the wild things? They neither reap, nor do they sow. But like us, they need to live where the food is, and that tends to be where the grass grows well.
We assume animals have an instinct that tells them where to settle. There’s reason to believe that some trace of this instinct is still present in us. In A Place of My Own, Michael Pollan writes about selecting the site for a small one-room structure on his property. He’s frustrated by the lack of literature on the subject. He finds some basic principles in De architectura, a first-century B.C. treatise by Vitruvius. It recommends building not too high (for winds) or too low (for poisonous swamp vapors), to lay the building out on an east-west axis with bedrooms facing east (for the morning sun) and the dining room west (for the dinner by sunset), and the principal direction facing south to absorb the bulk of the site’s sunlight.
He next considers feng shui. For choosing a building site, this involves mapping the land’s flow of chi, or energy, and picking a place where it flows unobstructed, but not too fast. He learns that a good way to find the path of chi is to clear your mind and walk the property; once, twice, three times. Wherever you find yourself walking again and again is likely a path of the land’s chi. You may find yourself on a game trail, or, as Pollan did, a cow path. This is a good sign: animal trails are considered reliable indicators of chi flow. Pollan eventually finds himself drawn to a particular spot, as the cows were, near the edge of a forest, looking out onto a meadow. It feels right, and happens to offer both yin and yang elements; male and female, upright and flat, trees and meadow.
Why would that feel right to us? One theory posits that we have an evolutionary attraction to landscapes that offer “prospect and refuge” — a good view of food/threats and a safe place to hide. Animals also prefer these areas; both predators and prey like to hang out near the boundaries of forests and fields.
Pollan eventually comes to believe that his architect friend was right when he suggested taking an intuitive approach from the get-go. “Think about it this way,” suggested the friend. “You’ve been hiking all day, it’s getting late, and you’re looking for a good campsite— just a comfortable, safe-feeling place to spend the night. That’s your site.”