The Pack Rat (Neotoma albigula), also known as the White-throated wood rat, has been in this region for at least 50,000 years. And it has been collecting things. Pat rats are troublesome around one’s home because they will eat insulation from automobile wires and get into the walls of a house. However, their habits have made them good desert archaeologists.The pack rat measures 8 inches long, head and body, and the tail is another 5- to 7 inches. The tail is covered by loose skin which can be shed to escape a predator. Pack rats are usually solitary. A pack rat nest is a loose conglomeration of twigs and grass, fortified against predators with cactus parts, especially cholla. The nest consists of tunnels and chambers with separate areas for food storage, sleeping, nursery, and waste products. There are often many insects in the nest feeding on collected plant material. Kissing bugs also inhabit the nest and feed on pack rat blood. Currently, the pat rat obtains nourishment and water mainly from feeding on prickly pear cactus. Its kidneys have evolved to deal with and excrete oxalic acid derived from the cactus. It is one of the few animals that can do this. (See my blog: Can you get potable water from a cactus for an explanation of oxalic acid.) That ability and its habit of collecting things is what makes the pack rat a good desert archaeologist. [...]