Gila Woodpecker When the Gila woodpecker digs insects from a saguaro for food, it cuts away diseased cactus tissue as well. The sap of the cactus hardens around the cavity and the resulting scar can become the home for the woodpecker or other desert habitants. Look for the 8-10-inch-long woodpecker in cactus deserts, brushy woodlands, and groves, and urban parks.