There once was a thriving winery in the hills behind Silicon Valley. The winery prospered, but the founders decided to move away, from what had now become expensive suburbia, to another place where the winery could grow in a more rural setting.

And so it was that the place was bought by a new owner who demolished the house, and filled in what had been the cellar and the swimming pool. And then the new owner decided to abandon his plans to build himself a new house. And so the land sat fenced of and undisturbed by human habitation for some years. The tall wire fence stopped the deer and other wildlife from visiting the property, but it became an ideal homestead for a rarely seen creature - the San Francisco Dusky Footed Wood Rat.

I don't have any pictures of this animal, he is nocturnal and very shy. But his living quarters are very obvious and easy to spot. The San Francisco dusky footed woodrat,   Neotoma Fuscipes Annectens,   is one of eleven subspecies of woodrat, and is found in the grasslands, scrub and wooded areas of the San Francisco Bay Area. While neither very rare nor endangered, it is nevertheless listed as a "Species of Concern" by the U.S. Fish and Wildlife Service.

The nests that these animals build, appear to the casual observer as curious mounds of twigs, sticks, and leaves. Some are low and dome-shaped; some might be up to six feet tall and pointed like tepees. According Bay Nature Magazine: If you could see inside a woodrat's house, you'd find a tidy little home: a nest bedroom or two lined with grasses and shredded bark; a pantry full of acorns and other seeds, leaves, and twigs for food; and several latrines for waste (a woodrat poops over 100 pellets a day!). The nests might have a few scattered California bay leaves to repel fleas. Food items that can be toxic when fresh (such as toyon leaves) are kept in a separate room to age before the rats move them to the pantry. When the latrines get full, woodrats clean house, shoving the pellets out into the forest, where they fertilize the soil.

There are a number of old wine barrels scattered around the property. Some were cut in half to be used as planters. The San Francisco Dusky-Footed Wood Rat has taken advantage of these structures in which to build nests. Again, according Bay Nature Magazine: When you see one house, look for others nearby. The daughters of female woodrats usually build or take over nests near their mothers', creating maternal neighborhoods of extended, multigenerational families. Some mothers "bequeath" their own nests to a son or daughter, then go to live in a second home nearby. But some father woodrats are literally driven up a tree-forced out of the female home after mating. They sometimes then build smaller nests in nearby trees. If you could look inside, you might find out why these rodents are also called packrats. Like their human counterparts, woodrats store lots of seemingly useless items in their homes: We have found tennis balls, eyeglasses, and Bic lighters and pens in abandoned nests in the Tilden Nature Area. Woodrat houses near mining camps and cabins elsewhere in the West have contained silverware, dentures, boots, and even dynamite caps.

Continuing with the article from Bay Nature Magazine: Woodrats share their houses with other animals, including mice, lizards, salamanders, snails, the occasional snake, and two kinds of ticks. Scientists have most closely studied the ticks, since they can infect people with the serious illness Lyme disease. The woodrat tick does not usually bite people, but it is responsible for keeping the bacteria that causes Lyme disease present in woodrat populations. It's the western black-legged tick that can spread the disease from woodrats to humans. So don't investigate an occupied nest too closely! Though they are large for a rodent (10 to 19 inches, including the tail), you'll probably never see a wild woodrat in the flesh. They're nocturnal, and even the light of a full moon is enough to keep them at home. But if you approach a nest at twilight, listen for the rattling sound woodrats make with their tails when excited or disturbed. It lasts for a few seconds, and can be heard from as far as 45 feet away

Wine Barrels aren't the only kind of scaffolding or infrastructure the rates will use to build their nests. More usually the nests are built in proximity to the trees that will provide the building materials for the nest, and any fallen limbs that are too heavy to carry or manipulate may just be used where they lie - and form the base upon which the rest of the nest is then built with smaller twigs. This particular nest is close to 6 ft high and is located just yards away from the other nests in the wine barrels.

At the entrance to the driveway, a rusted and dented old mailbox bears mute testimony to what once was here. Despite its abandoned appearance, the property is still a home - actually multiple homes - to an extended family that spans multiple generations of our own San Francisco Dusky-Footed Woodrat.