Extreme heat does not deter Harris's Antelope Squirrel from vigorous daytime activity. It is agile, scampering over sharp-spined cholla cactus without being pricked, and may sit on top of a cactus to look around. Learn more about the Ammospermophilus harrisii, more commonly known as a Harris's Antelope Squirrel, in this easy-to-read species overview by the Smithsonian's National Museum of Natural History.